I know, it's "never too late," but if someone never played Castlevania III until this week, I still consider it missing out. Anyway....
Despite everyone gushing over it, I've never played Yoshi's Island. Same for Majora's Mask (played Ocarina of Time for an hour or two and wasn't impressed, didn't feel the need to follow-up). None of the Phantasy Star games have come into my possession (including PSO). Never touched Kid Icarus. Robotron 2084 has eluded me to this day, as have Metroid Prime 1&2. For a more current title, Resident Evil 4.
*Edit* - others added after reading other posts
Chrono Trigger
Panzer Dragoon Saga
All of the GBA Castlevania games (although I have the double pack, no time for them yet)
Despite everyone gushing over it, I've never played Yoshi's Island. Same for Majora's Mask (played Ocarina of Time for an hour or two and wasn't impressed, didn't feel the need to follow-up). None of the Phantasy Star games have come into my possession (including PSO). Never touched Kid Icarus. Robotron 2084 has eluded me to this day, as have Metroid Prime 1&2. For a more current title, Resident Evil 4.
*Edit* - others added after reading other posts
Chrono Trigger
Panzer Dragoon Saga
All of the GBA Castlevania games (although I have the double pack, no time for them yet)