Diablo II
The Legend of Zelda
KOTOR

1. Metal Gear Solid 2: Sons of Liberty. Changed the way I see games, and life. Truly a great game.
2. Max Payne 2: Fall of Max Payne. Superb story and pacing, this game truly feels like a movie. I could play it over and over all day.
3. STALKER: Shadow of Chernobyl. Amazing atmosphere coupled with superior gun physics make this game a must for all shooter fans. An underappreciated classic.
Unofficial 4. Deus Ex. Do i really have to explain why? :P

Hmmm...so hard to choose....OK
1. Knights of the Old Republic
2. Tie Fighter
3. Wing Commander III

1) Doom
2) Thief II
3) System Shock II

These are those tough-but-fun to answer topics. Here we go:
1. Thief II
2. Chrono Trigger
3. Super Metroid
If I had to explain my choices and what kinds of games I love in a word, it would be: focus. A game with a clear idea of what experience it's trying to deliver and a clear plan and design to do that really excite me.

1. Ultima VII
2. System Shock
3. Ultima Underworld

1. Final Fantasy VI
2. Doom & Doom II
3. Aces of the Pacific
Oh, the memories . . .

Wow..three are surely too few :D
Anyway:
1) Planescape Torment
2) Jagged alliance 2
3) Fallout 1&2

Very tough to chose just three, it would be easier to chose three from every genre.
1) Fallout 1&2
2) Ufo: Enemy unknown
3) System shock II
(4) Jagged alliance 1&2)

Fallout 1+2
Total war's
hmm really hard
FF 8 and chrono trigger but also KOTOR1+2 nexus the Jupiter incident....i could go on :P

FFX
FFVII
MSG3

The good old:
1. Civilization
2. Traffic Giant
3. Railroad Tycoon

1. Baldur's Gate 2
2. Thief 2
3. Gothic 2
I must have an affinity for sequels, heh.

1. Syndicate
2. Resident Evil 4
3. Tie FIghter

Call to Power 2
Baldur's gate 2
Deus ex