Honestly, if you've never had a look at the Baldur's Gate "Trilogy", then you've been missing out big time.
Icewind Dale in a nutshell is a far less story-oriented version of Baldur's Gate, with some minor differences.
Planescape Torment on the other hand is dialogue heaven. If you enjoy banter, reading up on lore and really just love a good story, then it's the game for you. Kinda struck me as the least combat oriented game of the Infinity family, so if that's your cup of tea, then maybe Planescape ain't ;p But definately worth a look, and it has some memorable characters to be sure.
The Fallouts are classics, of course. Great story, great characters, great dialogue, great combat...it's got it all fellas. Just not the swords and the magic.
The Witcher is a good bet(not a party game...they just don't make em anymore
) if you like your storylines to be directly effected by your actions. Pretty sweet graphics, a "mature" storyline thats been well thought out and an interesting combat system.
Neverwinter Nights might also work for you, though I found the main story to be kind of...tame. Expasions did better, but still nothing compared to BG and PS:T. NWN2 was also pretty sweet, though linear.
For non-Linear gaming, Elder Scrolls is the way to go. Morrowind is better than Oblivion in many ways, in my opinion, unless graphics are your thing. Then Oblivion is your best bet. But why settle for one? Play both and decide for yourself.
If you want to try something different, then maybe Jade Empire. Not exactly what you're asking for, but I found it an interesting kung-fu RPG that mixes hand-to-hand martial arts, swords and magic pretty well. Mix in an interesting story, and you got guaranteed Bioware entertainment(you can't really go wrong with Bioware...usually atleast average gaming entertainment that won't leave you regretting the choice).
Hope you'll find something to waste whats left of the summer on! Steer clear of real life though...it's a bore.
Yours,
Raistlin.