System shock 1, 2?

Commandos series

COUNTER STRIKE 1.6 !!!!!!!!!!!!!!!!!!!!

i still play it , and its made in 1999

Thief & Thief II
System Shock & System Shock 2
Deus Ex
Half-Life
Doom & Doom II
Serious Sam: The First Encounter & The Second Encounter

Serious Sam serie <3 Painkiller maybe?

Is that a PC or a laptop?
You need at least a dedicated GPU. Buy a used PC or components and build a new(er) one.
If it's a PC you could install a Core 2 Quad processor although depending on the prices a complete newer setup may be better value-wise.

Maybe the original Deus Ex could run?

15 years? core2duo? that's 2006 minimum. Wizardry 8, fallout 2, gorky 17, unreal 1 and mb unreal tournament, deus ex 1. baldur's gate 1-2 (but better try 2, it's more user-friendly), morrowind, commandos 1,2,3, sam and max, leisure suit larry, JAGGED ALLIANCE 2, serious sam, quake 1-2. Tell me if you'll like something.

Dungeon Keeper 1 & 2

What genres do you prefer?

There are a lot of good RPGs which you could try. Baldur's Gate, Neverwinter Nights, Fallout, KotOR, probably even Morrowind.

I used to enjoy games like Rayman 2 and Little Big Adventure 2 on my old Pentium II pc about 17 years ago, yours looks much, much better.
Edit: I'll add Total Annihilation and old Tomb Raider games.

infinity engine games

Sega Genesis\Megadrive emulator for starters.
Then just games from the past, don't try to run games on high graphics, set everything to the lowest. Also is your pc strong enough to run flash games? Because I have a great amount of great flash games to recommend. Other than that, just play good old games that I'm sure you know of or can easily look up, old Need for Speeds, alot of RTSes, etc. Not sure what you have played so if I have to recommend good old games on a old pc, I can't realy say for certain.

I have exactly same machine.. (was)
Try this:

• All games in GBA & GBC emulator should be perfect, SNES and Genesis too.
• PS I emulator.
• DOS box (all DOS games)

Non emulator

• NFS 2, 3 (max Underground if i'm remember correctly).
• GTA II 100% sure, try GTA III
• Counter Strike 1.5 (YES it's 1.5) and Half Life
• Fallout 2, Deus Ex, Quake I, II, III
• Gothic 1, Divine Divinity, Sacred, Diablo I, II
• Warcraft 3 + Expansion, Starcraft
• Age of Empire I, II
• Caesar I, II, III
• Sims city 2K
• Duke nukem I, II, 3D

Oh and i recommended using windows XP for RAM.
If you not mind of windows support

Any particular genre you're interested in?

I absolutely loved Commandos-esque games like Desperados and Robin Hood: The Legend of Sherwood.

That is easy ... I don't have actually such a lame PC but had in earlier times ... so check

Mafia
Thief 1-3
Timeshift
Vampire - The Masquerade Bloodlines

There are some good old Star Wars games if you are in to that. For example Rogue Squadron and Galactic Battlegrounds should run fine.

even newer: e4700 is 2008 minimum ( http://ark.intel.com/products/34441/Intel-Core2-Duo-Processor-E4700-2M-Cache-2_60-GHz-800-MHz-FSB?q=e4700 )
but the graphic chipset is older and certainly the bottleneck :(

try teeworlds ( opensource / http://store.steampowered.com/app/380840/ )

Kotor, Oblivion, Arcanum, Baldurs Gate, Morrowind, Rayman 2, ...

Doom, AOE 2, starcraft, Quake...

You should save some money, to get a Core2Quad, if your mobo can handle it, or at least a low end gpu. Also RAM.

Fallout Tactics, Heroes of Might and Magic 3, Jedi Knight - Jedi Academy

oblivion?)) with 64 mb video memory?))

I'd recommend N++. If you can't run the version from this year, there is a 10 year old version for free on the internet.