SimCity 3000.

Best Game in the series, and one of the best soundtracks EVER!

I'd go with SimCity 4 with the NAM, and download the SC3k soundtrack to use as custom music.

I miss my CD key to RoN.  That was a great game.  I think at some point I'll get the Gold edition just to play it again.

The Guild is a great game for management/life sim.  You have to court a spouse, have kids, run a business, make money, have a political career... and then you die and pass it all down to your kid, who has a different set of skills than you did. 

Europa Universalis and Europa Universalis 2 are brilliant.

Thanks for all the great suggestions, i just got bored of my current games and was dreamin' bout simplier days when games focused more on story and less on shiny bits.

If you guys happen to have a higher-end pc, i'd suggest dawn of war II, and for the lower end, dawn of war.

Black and white 2! Fun game... Idk about well it would run, it tends to hog your ram and make you lag if you dont have a decent gaming pc...

If you happen to have a joystick, Heroes of the pacific is an excellent choice...

I just recently got back in to playing that. What a great game...I wonder if Solium Infernum is still due out by the end of the year? Based on his much I loved AE, that game is pretty much a day one buy for me.

In no particular order:

Dungeon Keeper 2
Imperium Galactica 2
Heroes of Might and Magic 2
Metal Gear Solid
Emperor: Battle for Dune (skip Dune 2000)
Silver
Little Big Adventure
Twinsen's Odyessy
The Secret of Monkey Island Series (they're all great)
Full Throttle
Indiana Jones and The Fate of Atlantis
Warcraft series (the RTS games, not the MMO)
Populous: The Beginning
Darwinia
Marathon
Duke Nuke 3D
The Elder Scrolls III: Morrowind
Baulder's Gate series
Black and White
DefCon
Star Wars: Dark Forces series (a.k.a. Jedi Knight series)
Icewind Dale
Planescape: Torment
Fallout series (third one isn't 'old')
Unreal
Diablo series
Vampire: The Masquerade Redemption
Vampire: The Masquerade Bloodlines
Hexic 2
X-Com: UFO Defense
Final Fantasy VII (doesn't work on Vista and has problems on XP)
Neverwinter Nights
Kings Bounty (spiritual predecessor to HoM&M)
MDK
Star Wars: Tie Fighter
Rainbow 6 series

That's about all I can think of now. These ones stick in my mind as classics, although there are hundreds I've played which don't pop into my mind right away. If you'd like further information on any of these titles, please let me know.

Blood ( you can find it for free at abandonware ). A 1997 fps game by monolith. Although you are gonna need dosbox to run it

Imo monolith's best game and one of the best fps games. The art style and level design are excellent ( moving train and the carnival are my favs), music is creepy in a good way, sound  is excellent, Calebs ( main character ) one liners ( many are from 80's horror movies) can rival Duke's one liners and finally the weapons are amongst the most imaginative and the most fun to use ( voodoo doll, akimbo napalm cannon, tesla cannon and a pitchfork are my favs ), enemies includ monks ( with tommy guns ) ,flying devils, clowns ( not enemies but killing them with the pitchfork never gets old),cerberus dogs, zombies and others

Did i mention it has a voodoo doll?

Besides blood more recent games i suggest are battlefield 2 ( not that old but imo the best online shooter with an active community even today), Max payne 1 and 2, Serious sam ( mindless crazy fps action with some of the biggest boss in any game and some of the best weapons and running bulls ) ,  first FEAR from monolith , Unreal tournament 2004 ( best UT game imo), the very first unreal ( the 1998 one )

ZehDon, how can you say to SKIP Dune 2000?!?!?! I have and love that game, though I haven't played Emperor Battle for Dune.

X-Com: UFO Defense (aka UFO: Enemy Unknown) is probably the most awesome turn based game I've played in my life, matched just by Jagged Alliance 2.

Well, Dune 2000 was a slightly tweaked version of Dune 2 with updated graphics, while Emperor was it's own beast and more inspired by the original classic than a remake of it.

And I couldn't agree more Tuco.

The Best 1 player, old game right now for myself, is Evil Genius.

Lemmings (the for Windows version works fine on my XP setup)

Sid Meier's Alpha Centauri

Day Of The Tentacle

hmm. I've never played Dune 2 or Emperor. I'll have to try and get a copy of Emperor then.

Though, have you read any of the Dune series, and does Emperor match up with the books? Note that Dune 2000 (and likely Dune 2) do not match up. Like, barely, if at all.

If you think rise of nations might be for you perhaps you should try rise of legends (or perhaps that is too recent)

Emperor is similar to Dune 2000 and Dune 2, it's set in the Dune Universe, but doesn't follow the events of the book. The story is kinda camp, like the Red Alert series, however it's still fairly good. Worth a play through if it's not too expensive.