First up on the list is the Dot hack GU series. I've been playing through volume one and i have literally gone 18 straight hours playing it. A hack and slash thats not quite just a hack and slash style combat that's repetitive yet addicting. An interesting setting and story that keeps me playing and tons of side quests. The only problem the game has, a huge, glaring, obnoxious problem, are the characters. I'm not entirely sure how far into the game im at, but the characters have been just terrible since the first couple of seconds. Hasaeo, the main character is an arrogant idiot (yet seems to be the only one who realizes they're still just playing a freaking game) and the rest seem to be horribly innocent, cliche retards who seem to have forgotten that they are in fact in a video game. As annoying as they all are they all do seem to have the occasional bad ass moment though, so its not entirely bad and its no reason to stop playing.
Next on the nostalgia list is Shin Megami Tensei Persona 3. This game is so JRPG its almost hilarious. It's very fun, and the story is amazing and dark. It never gets old watching the Persona invocations (you know, a magical bullet to the head) The game as a whole does get old really quickly as the game play is very repetitive so i can only really take it in small doses, but those doses are fucking great. You play a Japanese high school student that has the ability to stay awake during the dark hour where all other humans drop into a coffin and sleep for an hour to protect them from crazy demon monsters and wake up without a clue it happens. This kid joins a group of other high school kids in his dorm that fight these demons using "personas" fractions of their mind that can form into bad ass looking creatures with cool abilities. The main character can actually summon and use every persona instead of just one which leads to some cool customization of party roles. You play half the game in school doing random social events and making friends to strengthen social contacts which in turn strengthens your personas. The other half of the game is played at night after school when you can take your team to the "tartarus" tower where all the demons come from. Working floor to floor killing demons and finding sick gear until you feel beat and return to sleep and then repeat it all over again. Slightly repetitive, but really fun and dark as hell.
I just picked up a copy of another interesting and well rated RPG in last days of the PS2. Rouge Galaxy, a fun game half single player and half online. haven't gotten a chance to play too much of it, but the combat is a lot like Persona 3 and therefore very fun.
Last but not least I have been playing through Fatal Frame 2 again. I just love it. The extremely fucked up story. The creepy as hell setting and atmosphere. The combat requiring you to get yourself as close as possible to some horrific looking ghosties. FF2 is just an amazing PS2 game and ranks as one of my favorite games of all time.
If I can get out of this PS2 kick I just might play through The Darkness 2 and Hitman Contracts.