yes. story, characters, level design and look, music
and of course freedom - what can you do ?
I have bought and read this a couple of months ago, I can recommend it aswell
I guess you dont like Metal Gear either. I love Final fantasy (7 and 10 in particular) and the Metal Gear Series.
A great thought-out story is just so emerging.
I also likes Heavy Rains gameplay, but unfortunately I thought the story was dull.
And I think FF X had the best gameplay of all - but thats just me. Being able to strategize without timelimit. Maybe FF 7 is better, but I think FF 13 is too frantic for you to come up with unique tactics amidst a battle.
Also note for FF X: most people play of course long after the end, getting all the special stuff, and as everybody knows, gameplay-wise a JRPG only really begins after the main story is done; because only then you try optional dungeon, reach insane levels and stuff - Most FF games are like this and also for example the star ocean games, which I also love
talking about RPGs, I would call Mass Effect 2 a RPG, and since its easily one of my top 5 games, its a good example for a great RPG too