I don't think I could ever just list 5 so going to keep it as short as I can.
1. Everquest 2/Everquest I really loved both, Everquest was the first game I spent years upon years with. So many new experiences it was just brilliant. Everquest 2 however I enjoyed the pvp aspect on Nagafen a lot but more than that I met gamers that I still play every new MMO with to this day. I will game with this group of guys/gals until the day I stop playing MMO's.
2. Might and Magic 3-8, I really liked all of these. I probably would have liked 1 and 2 just never played them back in the day for some reason. These games solidified my love of party based RPG's.
3. Wing Commander all of them but Privateer shines a little more brightly than the rest. I was so dedicated to this game that I would actually write notes while in High School about what I was going to do later( I did this with Wizardry, Might and Magic and X-Com as well). What a wonderful game to be so open and for its time, just wow.
4. Wizardry all of them but I liked 8 the most. I know most say 7 or 6 is the best but for some reason I liked 8 as Sirtech's last gasp. I knew they did not finish the game but what was finished I loved so much. I start up a new game of this every couple of months. I use a party randomizer to pick how many characters I make 1-8 and what race/class combo's I use. I still find it a ton of fun to play. I have played all the mods as well.
5. Hammer of the Gods was a great TBS from New Age Computing right before HoMM and just after King's Bounty. You did quests for Nordic gods and got their favor in the form of heroes to fight for you or a ton of other types of bonuses. I actually just downloaded this game again about 2 weeks ago and still enjoying the hell out of it.
6. Heroes of Might and Magic 1-4, why oh why can't they just revisit HoMM 3 and make a real sequel? HoMM 5 and 6 were just abominations compared to the others. I miss this series so much and still buy every new HoMM released only to be dissapointed over and over.
7. System Shock 2, whoever said this game was not as good as we thought I totally disagree. This was some creepy ass cool shit. I play this game to this day and often.
8. Call of Duty 1-3, Medal of Honor Allied Assault, Pacific Assault all but the most recent one. I so enjoyed the single player campaigns of these games. I wish they did not just CoD into a multiplayer treadmill with limited single player action. I still play the newest ones in these series but don't enjoy them as much as I used too.
9. Bard's Tale 2. I liked all of the Bard's Tale games but 2 was my favorite. I am not sure why but I just played more of 2 than any other BT.
10. X-Com. I doubt I need to explain this.
11. Wasteland. The skill point and skill leveling system were so far ahead of their time. This and Dragon Wars were two of my earliest RPG's that I always go back too. I cannot wait for the new Wasteland game!!
12. Final Fantasy Tactics. I spent so much time in this game. I love the summoners. I loved getting the mime class going. I just loved this game all around.
Honorable mentions to LittleBigPlanet(so much creativity allowed with these games), Resident Evil, Deus Ex (original one), Twisted Metal 2 and Black, Super Mario Brothers(i was different than most people I played these a few times after I beat them but after that meh done), Goldeneye 64, Zen Pinball, MLB series, Madden Football 94-2002, NHL 95(sergei federov and steve yzerman had like 8 goals each game apiece), SSI Gold Box DND games, Jagged Alliance, Darklands(great old dos RPG), Knights of Legend(great old rpg with a crazy combat system and a race you could pick for party members that could fly), Police Quest 1 and 2, Dark Sun 1 and 2(used to play these in my huge lecture hall classes at University of Maryland), AutoDuel, Roadwar 2000, Lands of Lore series....sorry I could just keep going on and on I made this into all my old favorite games =(. My bad.
P.S. Keef the Thief, you had to disarm traps and whatnot and had active combat well as active as it could be in 1989.