Currently at 3, Fallout 1/2 and UT.

I bought a lot of the interplay games if i hadnt bought unreal series and stratagy plus games off steam i would have bought them here but heres what i have bought so far.
Fallout 1
Fallout 2
Fallout tactics
Freespace
Freespace 2
Hostile waters
Sacrafice
Original war
Battle chess
Stonekeep
Invictus
Giants
Descent 3
Max
Premier
Soldiers
Toca race drivers 3
Good collection for the winter months :)

2
sacrifice
SHOGO
and got one free Lionheart.
I have around 10 games which still needs to finish before I buy anything new

I don't have much time for playing right now so just one - Fallout. But I'll definitely buy more. After Fallout 2 and Tactics I'm thinking about Unreal Gold.

I have:
Fallout 1
Fallout 2
Fallout Tactics
Operation Flashpoint GOTY
I will probably buy Unreal Gold and Unreal 2 next.

Bought 2 more games and got 1 free due to the current promo!
Added Jagged Alliance 2, Project IGI 2 and Conquest Of The New World to my repertoire..
Got my super-understanding future-wife to buy me those. :D

Only 7, I'm ashamed to say. I'm a slow player:
Descent 1 & 2
Fallout
Fallout 2
Freespace 2
Just got:
Unreal Gold
Gothic
Citizen Kabuto
So nice!

Oh c'mon. Buying 7 is much better than pirating 7 isn't it? :D
I also have 7 games on my list due to my un-unlimited funds.

lol :P
Well, I hold back sometimes in the hope that something better is around the corner... I mean, Disciples 2 was release not long after 1, for example.

Eleven.

18. Didn't realize I had gotten that many.

Currently only two...

NECRO-EDIT!:
Arx Fatalis
Battlechess (give a game/get a game thread)
Blake Stone Aliens of Gold
Blake Stone Planet Strike
Darkstar one
Descent 1 + 2
Descent 3
Duke Nukem 3D
Earthworm Jim 1 + 2
Fallout
Fallout 2
Fallout Tactics
Freespace
Freespace 2
Giants- Citizen Kabuto
Gorky 17
Heroes of Might and Magic
Hostile Waters - Antaeus Rising
Ishar 1 + 2
Jagged Alliance
Jagged Alliance 2
Lionheart - Legacy of the Creator
MDK
MDK 2
Messiah
Oddworld - Abe's Exodus
Oddworld - Abe's Oddysee
Perimeter
Postal 2
Rainbow Six
Redneck Rampage Collection (off-topic: I managed to type Redneck Rapmage first...)
Rise of the Triad
Robinson's Requiem Collection
Sacred Gold
Sacrifice
Second Sight
Septerra Core
Shattered Steel
Shogo: Mobile Armor Collection
Stonkeep
Stronghold
Stronghold Crusader
TOCA Race Driver 3
Waxworks

(In the voice of an overexcited sports announcer): THREEEAAAAD NECROOOMAAAAANCYYYY!
Bought 27 games so far.

Over 9000.
Seriously? 17 (exluding free games).