Well instead of naming mainstream series/games... I will go with Games and series really not known or played that deserve some Luv...
Zero Escape Vol 1: 999: 9 Hours, 9 Persons, 9 Doors and it's sequel Zero Escape Vol 2: Virtue's Last Reward(NDS, N3DS/PS Vita)- Best Video Game story I ever experieced in 999, plus a killer soundtrack and memorable characters. VLR story and OST is also gold and the Characters cast is strong as well, and improved gameplay and graphics over the first one makes it the better of the two games. Not to mention both stories have more twists and turns than a game of porno twister... If you like visual novels/solving puzzles look no further... these are your holy grail of games.
Castlevania Dracula X Chronicles (PSP) - A remake of the Classic Castlevania: Rondo of Blood and does it justice with better graphics, voice acting and animated intro. The biggest improvement from it's predecessor is the soundtrack that'll make you cut up wooden broomsticks, make a wooden cross and REALLY become a Vampire Hunter. Oh and it has the OG Game AND Castlevania:Symphony of the Night as well. Best $10 I ever spent in my life.
Fire Emblem: Path of Radiance and Radiant Dawn (and pretty much the whole Series) NGC and Wii) - Sure Radiant Dawn is an acquired taste but if you enjoy a challenge while testing your stragetic wits along with memorable dialogue and characters, look no further (plus comes closest in creating a Medival Darth Vader). Radiant Dawn is rated low unjustly by critics because of the supposed inferior graphics from PS3 RPG titles and difficulty. The whole Fire Emblem series is underlooked in paticular. More gamers should know about the exploits of Ike, Lucina, Hector, Lyndis, and Marth.
Anybody else have any recommendations?