Idk, I liked Assassin's Creed 1 for its gameplay and story, even though it got kinda repetitive after a while. The rest of the creeds I played purely for the storyline, up to Black Flag, where the fucking storyline was missing. The gameplay did get boring around after the 2nd.
Heretic II is a really neat 3rd person shooter of sorts... It might be nostalgia making me say that but still...
Personally I like HOMM5 more than HOMM3, but please don't kill me xD
King's bounty is like HOMM5, but more like those roaming missions without a town.
Myst Series - If you're a fan of point and click adventures with awesome storylines, this is a must fucking play, the best series ever
Silver - I put it here mostly because of nostalgia, it has kinda neat story and creative combat (even though most people say it is weird as fuck)
Terraria - 2D minecraft with 1000x more content.
Ys Origin - The best JRPG I've ever played. Incredible character development, even though it has its cheesy moments.
HoMM3 - Prefer HoMM5 (hides under a rock)
Knights of Honor - Never heard of it
Jedi Academy - Neat, but kinda buggy in my experience. Still played through it 2-3 times.
Tzar: the burden of the crown - I'm quite surprised you put that on the list. It is a neat RTS with HUGE battles and awful movement system. Most of all, it is made by a bulgarian company :3 If you feel the nostalgia, here's the game patched for modern systems.
AoE1, AoE2, Age of Mythology, AoE3 - Timeless RTS classics.
Battlefront II - heard of it, but never played it.
WoW - TBC and WotLK were the best expansions. I've played Cata and it's crap, not to mention the next ones...
Chivalry - My brother plays that a lot, seems like a nice game.
The Witcher Series - I'm planning on playing those :3
Diablo II - You have no idea how much I've played this one.
TES: Oblivion - I've played very little of this one, I tend to play more skyrim.
Mortal Kombat 4 - It has a PC version?!
Minecraft - Played it a lot and realized the survival mode sucks complete ass. I only build in creative now.
Spore - Oh, I remember this one, I used to make dick creatures in it xD
PoP - I've played it very little, until I got stuck on some stupid parkour on the ceiling.
Thief - Played it only up to the zombie level, where I didn't know where to go.