1) Final Fantasy 6 - This game pulled everything in for me, a strong main plot, lots of side quests, loads of characters with varying levels of back story, easily played well over 200 hours in all the years of gaming that I have played. Holds a sentimental place for me, with just how many years it holds up as replayable.
2) No More Heroes series - Love this series, the characters, plot, the twisted nature of everything. Cosplayed as Travis, built the Bloodberry even. Wife went as Shinobu, love it that much.
3) Mass Effect series - Each game feels like the most complete titles that I've played, there is so much to explore, so much for choices affecting other choices, and being a sci fi fan, everything clicks. Three will rock my socks off I'm sure.
4) Super Mario World 2: Yoshi's Island - One of the few games I have gone through and 100% completed. The art style makes it fun & light but the game has plenty to do, find & explore.
5) Project Justice - One of my first DC game purchases and a still my favorite for the system.