TheHoodedMan:
I started with the "Prince Ulthers Imperial Dwarfs" Box and the "Bugmans Dwarf Rangers" Box. The 3rd Box I bouhgt was the "Chaos Dwarf Renegades" Box. After that I collected vanilla dwarfs and chaos dwarfs parallel.The 2 boxes are top notch, no wonder you fell in love with the dirty little fellows; -).
Now I own a Chaos Dwarf army, a vanilla Dwarf army, a (Dark) Elf army, some 3rd Edition Slaan models, some Undead modles and some Witch Hunter models for Mortheim.
:hashut
Zanko
Abecedar:
7th Ed battle for Skull Pass was where I started. My son took the dwarfs and I the goblins. I built up the O&G to 10,000+ but meanwhile, various forays into ebay looking at olde slayer models for him led me to the Chaos Dwarfs and the start of collectoritis for me.
Jackswift:
I started with Sisters of Battle 20 years ago… back when their list was tiny with no official rule book and like 20 official models give or take. Eventually branched into a Dark Elves for WHFB (sold the army later but still have some stragglers). Now for fantasy KoW I have CD supplemented with some Celtos Orcs and the occasional dark elf + a 2k size Nippon army made up mostly of Clan War models. For 40k (now Warpath or One Page 40k) I currently have 5k Sisters of Battle, 2k Tron Eldar, 3k Thousand Sons (second army. Sold the first one I built), and 4k Orks including titans and flyers for most of these armies for mass battle. Bear in mind that most of these haven’t been built on for a few generations of rules and don’t see much table time these days. I’ll likely be divesting of a significant portion of them in the near future.
Willmark:
I started with the "Prince Ulthers Imperial Dwarfs" BoxI've got these guys and still sporting their original 1990 paint job! x.x
Zanko
Will Liam:
Orcs and goblins was my first army before Chaos Dwarfs so its handy that they can be used togeather as a huge related army
Miasma:
My first lov…army has always been Night Goblins. I sold most of the original models that I had (And now severely regret) Clubbers & Netters, Cave Squigs, Squig Herders, Stone Trolls… urgh would love to get them back but then next army was Vostroyans (oh look all have Big hats and metal…)
Sjoerdo:
Started with Chaos Dwarfs 
In 5th edition, the old big hats. Sold this army.
Then moved on to Vampire Counts, and starting collecting 2nd editions Chaos Dwarfs.
Sold the VC’s moved to Orcs and Goblins.
Sold the O&G’s and moved to Nurgle.
Sold the Nurgle army and started playing a full 2nd edition army of CD’s in 6th edition Warhammer.
Traded all my painted 2nd edition CD’s to a good friend for unpainted ones and stopped playing all together, just sculpting and collecting.
Abecedar:
Started with Chaos Dwarfs :)Legendary
In 5th edition, the old big hats. Sold this army.
Then moved on to Vampire Counts, and starting collecting 2nd editions Chaos Dwarfs.
Sold the VC's moved to Orcs and Goblins.
Sold the O&G's and moved to Nurgle.
Sold the Nurgle army and started playing a full 2nd edition army of CD's in 6th edition Warhammer.
Traded all my painted 2nd edition CD's to a good friend for unpainted ones and stopped playing all together, just sculpting and collecting.
Sjoerdo
Abyssalmatt:
Chaos dwarfs were my first; skaven were my second, I have 20,000+ points of skaven; had 4k bretonnians I just got rid of, and 3k dogs of war.
gsteelwraith:
I still have my old Chaos Armybook and Codex, those books were the absolute best GW ever put out. I was happy when I scored my Chaos Dwarf Armybook last year.Chaos. Always Chaos. Back when it was a single book. But if I have to choose now, it's Warriors of Chaos. Well, now-ish. I have no idea what's going on in AoS.Agreed here. I thought the 5th Edition rules (not necessarily the power level) for Chaos was the best they have ever done.
Xander
Willmark
Malorndk:
5th edition: O&G - learning to paint was haaard xD
6th edition: Dark Elfs - Rules where baaaaad, then 7th came 
Still have everything! But shared with my brother
Unzul:
Orc and Goblins
WAAAGH!!!
Enjoysrandom:
I started collecting Blood Bowl figures and decided, after collecting a fair few teams, that I preferred the Chaos Dwarves.
I was originally leaning more towards a Chaotic Malal army with Chaos Dwarves as the main focus… but the 4th/5th edition Dawi’Zharr seemed to have more character!
Now days I have a bit over 10k using Tommy H’s point system… although neglected there are still plenty more big hats to add… and a seemingly continuous list of manufactures ready to produce more, nudge nudge Admiral, many more of your models are needed!
Hashut’s Blessing:
Oddly enough, for me it was Chaos (my very first army) and Dwarfs. Almost like finding these guys a decade and a half ago was merging my two favourite armies into one, but with much cooler stuff to boot
Willmark:
Woah a HB sighting!!!
ashur:
I started with dwarfs, then lizardmen, then CD. Then I fell in love with the kislevites.
Horace:
I started with 4th edition Orcs & Goblins, my brother took the High Elf contingent. Since then I’ve added Dwarf, Vampires & Daemon armies and I have access to my bro’s Empire, Chaos and Elves.
I always liked the Chaos Dwarfs and envied my friends army of them so thought I’d put together some big hats of my own. Looking forward to playing through Tamurkhan once I have enough to throw down on the table
Hashut’s Blessing:
Woah a HB sighting!!!!!It does happen on occasion ;)
Willmark