Love me some Star Ocean but I think that's a series where the game aspect (item creation and battle system) outweigh the always awful character and story scenario. FF13 was middling in every regard except exploration where it provided none.
I love Star Ocean 2, and the first to a less extent [PSP version], but I just couldn't stand Star Ocean 4. The story and characters tanked so hard so fast that I just couldn't stand to play anymore, despite the few things it did right initially to get me hooked. So, instead of playing SO4 further, I'll just go back and replay the first two. It's easier that way.
Combat isn't the only reason I find jrpgs fun or else I'd love FF13. I love exploration as well, but I prefer the way jrpgs do it (SMT, FF12, DQ, usually for the sake of gameplay) over how wrpgs do it (usually for the sake of story). jrpgs tend to usually make more interesting and cohesive worlds to me.
Well, to me, exploration IS the gameplay, as much as combat is. That might seem a little strange, but hoofing it across some monster-filled land in search of some ancient ruins that might be filled with treasure [or not] is as much fun as a good combat system. I like immersing myself into the game world and wandering around, not really with any sort of purpose other than to see what's at the top of the next hill. Whether that's for the story or the combat, it doesn't really matter. Also, whether that's from a handful of JRPGs or from some janky WRPG, I'll take it.
I'm also far less forgiving with regards to the cohesiveness or fantasticality of the world itself. I'll take the dull, confined depression of Morrowind as readily as I'll take the bright and colorful world of Final Fantasy XII.
I guess this is why I like the Mass Effect games so much. They feel like jrpgs with an wrpg skin.
I'm not really sure how Mass Effect is really that much like a JRPG. If anything, it's an action game [or third-person shooter], with a few RPG affectations for good measure. Not that I have a problem with that, but I just don't see how it resembles a JRPG, especially with how it handles progression and player choice.
Mass Effect's not exactly nonlinear, of course, but it does offer some player control over the order of progression for most of the game events, barring a few key segments, and there's the good and evil split which gives you some control over what kind of character you play as, which, again, isn't so much inline with what JRPGs are doing.