Played alot of games since 25 years and in no particular order here are some of my favorites:
Dominions 3 (But ofcourse
)
Civilization 1-4
UFO: Apocalypse
Jagged Alliance 2
Chaos Overlords
Medieval Lords
Empire
Stars!
Reach for the Stars (The OLD version)
Emperor of the Fading Suns (although it was very buggy MP games was extremely fun)
Victoria
Crusader Kings
Europa Universalis 1-3
Wastelands
Elite
Dwarf Fortress
Battlefield 2
Operation Flashpoint
SWAT 4
World War II Online
Star General
M.U.L.E.
Frantic Freddie
Lords of Conquest
Railroads West!
Deuteros
Imperialism 2
Colonization
Master of Magic
Reunion
Sid Meiers Alpha Centauri
Space Empire 4
Battles of Napoleon
Colonial Conquest
Advanced Tactics
Rise of the West
Swords of Aragon
Warlords 1 (and only 1)