Willmark:
Since there are a lot of new members these days I figured it would be good to revisit this.
We are a special breed, some might say insane for supporting and army that has ever had a really army book!
I’ll start: for me it was the RH army list and a Chaos Dwarf mention in WD #218ish that got me going.
I’ve never been a big dwarf player let alone evil armies, prior to this I was a High Elf player so go figure.
How about you?
Dhark:
I always loved the Chaos Dwarfs for their background. I like the idea of their pact with the Chaos just for surviving and their bat habit of enslaving and wasting the whole Dark Lands. 
They are the perfect warriors of Chaos, but with a reasonable background.
The problem for me was: I don�?Tt like their orcish teeth and their strange nose, but the Polish designer Scibor solved this problem. Now I am a proud Member of the Chaos Dwarf players and I guess this won�?Tt change for a long time.
I play a lot of armies next to the CD�?Ts, but the evil Dwarf captured a special place in me :cheers
Regards
Dhark
Anonymouse:
For me it’s the fluff-part as well: I love the background of a race known for its honesty (well, honor and stalwart behavior at all costs ranks as ‘honest’ in my book) and righteousness, to have fallen from grace and become exactly what they -by nature- are not. I started out as a HE player and dabbled in a dwarf-army for a while because I always liked the concept of a desperate fight of good against the overwhelming odds of evil.
The way the CDs effectively betrayed their own character, especially as many fanfiction-outlines, makes them extra interesting to me.
Another part of my attracion towards the CDs has to do with the newer models (Cannon) who have turned away from the comical big hat style (sorry to all you hat-lovers: I’m a skull/mask man). I always loved the old Marauder minis, which to me at least ooze malevolence. The way the Hobgoblins were modelled was something I did like from the very begin, though.
I never like Chaos, Daemons or Beasts that much, but I can’t compare the new-style CDs with any of the other ‘evil’ races.
Modelwise, I think the grim-looking fanmade models surpass the original in so many ways.
The fact that their background has been developed almost completely by fans, instead of a uniform GW-look on how things should be, appeals to the anarchistic nature of yours truly 
Loki:
For me it was the big hats that got me hooked :hat Really liked the style of them and the back ground to Choas Dwarfs as a whole, and its also great to have an oop army, its much more interesting to play an army that most prople have not seen before or know very little about rather than jumping on the band wagon of what ever the latest army that has just come out.
Spikes:
I like CDs for their gameplay.
Throwaway unreliable slaves coupled with reliable slow dwarves. Well obviously if I had none of the flaws it would be even better but no army is perfect, right?
Baggronor:
I started them because they were a cool modelling project but then the evil midgets took over my life 
Border Reiver:
In a twisted way I was into them before I was into Warhammer itself.
In my immediate post -university days (1993-94) I played AD&D, and was looking to start the year with a new character for the group - a rather nasty dwarf assassin and needed some inspiration when I came upon the WD presents book that I picked up…
Flash forward about a year and I’m no longer playing D&D, but I’ve got a new hobby and the rest is history.
Since then, it’s been the thrill of being one of the few players in the area with this unique army.
stevedosdedos:
For me its just something a little different, and i am enjoying converting a whole army!
Never really done any sculpting with green stuff before and was inspired by Xander’s tutorial videos.
Haven’t actually played a game with them yet, but sculpting is coming along nicely!
Thommy H:
I have no idea why I started them back in the day. I guess they were part of my formative Warhammer experience because, years before I ever bought a figure, I had some friends (well, sons of friends of the family, so we only saw each other a few times a year I guess) who played and they told me lots of stuff about it and I absorbed the models and rulebooks they had around. I remember seeing Chaos Dwarf Man o’ War ships in one of their White Dwarfs and asking what the deal with them was and stuff like that. This was very much the glory days of the red period and, some time later, when I got into Warhammer (maybe six months after getting into 40K) it was the 5th Edition box set that started me off. So I tried Bretonnians for a bit and they were okay (I never really gave the Lizardmen a second look…) but I wanted something new, and I somehow settled on Chaos Dwarfs for my army. Don’t ask me why, except that back then they were as valid a choice as any other. In the 5th Edition Battle Book there’s a two page spread of two armies fighting - a representation of a ordinary Warhammer battle, if you like - and it features Chaos Dwarfs and Skaven. So they were just a normal army back then, and very characteristic of the red period. Anyway, I collected them for a year or so and then they went OOP. I moved on to other armies and briefly revamped them when 6th Edition came out, but that was it.
Many years later, a random conversation with an old friend led to an offer of playing a few games of Warhammer. I looked to see what I could scavenge from my bitz box, and realised that I had an awful lot of Chaos Dwarfs in there. So I repainted the whole army and…yeah…the rest is history. I stuck with them because I like obscure and heavily themed armies and it’s fun to have something hardly anyone else has.
Time of Madness:
First got into them because of the flexibility of the army. With the ability to have rock hard dwarfs supported by magic and greenskins they were fun and flexible to play with.
I Played Chaos dwarfs back towards the end of 5th edition. When the RH list came out I sold my entire painted army and moved on. I’ve made a couple of attempts to get back into them and have finally put together a decent sized force.
Time of Madness
Fequiil:
for me it was like this: i started warhammer with dwarfs(i’m small), and then i got into chaos.
and i wondered to myself: what if those two where mixed?
and then i heard of chaos dwarfs for the first time, it was a love at first sight.
rabotak:
being a long-time fan of strategy games, be it board- or pc-games, a couple of years ago, i met a guy who told me about warhammer and i really loved the idea of that game, but the money i would have to spend for the hobby drove me off, and i didnt know which army i wouldve started anyways…i love dwarfs but gamewise they sounded quite lame to me, elves were no issue (then:)), and i absolutely dislike humans… (un)fortunately, that guy lent me a copy of the old 5th ed battle book, and instantly I fell in love with these cute funky little assyrian dwarfs, even more since I´m studying assyrology… now, 4 years later, i got about 6 to 9k of them (depending on the list)… and three other armies of 6k points, speaking of the cost factor x.x
Thorne:
The challange to make a unique force that will scare the hell out of any opponent before you even roll a dice !
Firehammer:
At first I was not enthusiastic: The bighats and sorcerer stilts looked like cheap jokes on an size related inferiority complex. And the old red paint job didn’t help either to make them look good. So I looked elsewhere.
D&D got me interested in all races of the Underdark, including Drow (Dark Elves) and Duergar (Evil Dwarves). So I revisited the Chaos Dwarves using my old Citadel catalogue and liked the Assur/Babylon look of the CD faces. I bought the old army book and learned about their fascinating background, including a good explanation of the stilts.
At that time the current Warriors of Chaos army book was released, and in a 9-5 inspirational flash (9pm-5am ;)) I got a lot of “count as” ideas to fill all the slots with something from the CD background, starting with CD warriors as Warriors and Bull Centaurs as Knights.
Army is now complete in boxes, awaiting assembly and painting.
Kered:
I am a long time player of daemons and I fell in love with the hellcannon and the new style of chaos dwarfs.(I still have a soft spot for big hats.) I didn’t do much for a wile and then I fond my brothers old RH book and fond there was a Chaos dwarf list at the back that I had never noticed before. I was intrigued by the fluff and odd and unusual army style with daemonic siege weapons
and these thing called a-r-m-o-u-r saves and lack of core units with ward saves.
I also was fond of the old marauder dwarf from my old citadel catalog.
Da Crusha:
I originally played good dwarfs and while on ebay I noticed the marauder style chaos dwarf models and they seemed pretty cool. then I went to a tournament about 2 years ago and I saw some guy playing with a beautiful big hat army and we talked for a little bit about them. I had no idea any body was even trying to use them. when I got home I was inspired by the thought of using an army that is rarely seen, but I dont particularly like big hats. so I began collecting marauder style chaos dwarfs… and now I have about 200.
tjub:
Chaos Dwarfs were my first army about 15-16 years ago and when I got back to WFB much thanks to CDO a few years back the seemed the natural choice. Something to work with long termed, and since I almost only play with a close group of friends its never any problems with whats legal/official or not…
G.2:
I always like something that is a little bit strange and unconventional. I did start collecting an Empire army when I got back into the Warhammer hobby, but to satisfy the unconventional part of my collecting, I collected ‘old-school’ metal figures. Once I discovered the Big Hats, I was instantly attracted to them, as they looked really silly but in cool sort of way. So basically for me, it was the models, and the fact that are a little bit uncommon.
furrie:
I liked the idea to just convert an entier army and then I found this place and saw how helpfull everybody is here. That is the reason I started chaos dwarfs (and ofcourse evil twisted dwarfs, how much cooler can it get :P)
Neil:
Because since the Ravening Hordes book very few other players use them. I’ve always liked the less popular options.