Conquered!!
The following list of games are all games I have "beaten" in my many years of gaming. 

Nintendo (8-bit)
Battletoads
Legend of Zelda
Legend of Zelda 2
Super Mario Bros.
Super Mario Bros. 2
Super Mario Bros. 3
   and basically any other game I rented 9-13 years ago which I can longer remember

Sega Genesis
Aero the Acrobat
Echo the Dolphin
Echo the Dolphin 2
Greendog
High Seas Havoc
Rocket Knight Adventures
Shining Force
Shining Force 2
Sonic the Hedgehog
Sonic the Hedgehog 2
Sonic the Hedgehog 3
Sonic and Knuckles
Sonic Spinball
  again, all of the hundreds of games I rented but can never remember

Sega CD
Lunar: Silver Star Story
Lunar: Eternal Blue
Popful Mail
Shining Force CD
Sonic CD
Vay

Playstation
Castlevania: Symphony of the Night
Chrono Trigger
Chrono Cross
Crash Bandicoot
Crash Bandicoot 2
Crash Bandicoot 3
Crash Team Racing
Fear Effect 2
Final Fantasy VI (remake)
Final Fantasy VII
Final Fantasy VIII
Final Fantasy IX
Final Fantasy Tactics
Kings Field
Legend of Dragoon
Lost World
Metal Gear Solid
Parasite Eve
Parasite Eve 2
Resident Evil
Resident Evil 2
Silent Hill
Vagrant Story
Vandal Hearts
Vandal Hearts 2
Wild Arms
Xenogears

Playstation 2
The Bouncer
Final Fantasy X
Frequency
Gitaroo Man
Grandia 2 (Dreamcast version)
Metal Gear Solid 2
Rez
SSX
SSX Tricky
Zone of Enders

Gameboy Advance
Advance Wars
Castlevania: Circle of the Moon
Metroid Fusion
 

Currently Working On
Final Fantasy IV
Final Fantasy V

On a side note, there are many many other games I have beaten but I just cant remember them since in the old days I would rent games and beat them within a week.  For the most part, this list shows the  RPGs I have conquered mainly because those are the games I remember the most.