Eh might as well do mine.
(only including the ones I actually played and finished)
MDK2: decline over the first, but not that bad in its own right. Ok-ish I guess.
BG1: sue me but I liked it. Yes it's mostly empty maps that they filled up with trash mobs. Yes, RTWP. But aside from the RTWP it was a decent computerization of AD&D2, the parts of the plot that didn't deal with the Bhaalspawn were subtle and quite interesting (too bad this part is not the one people remember), despite the trash mobs it had quite a few fun set piece battles (usually the opposing parties) and the expansion added Durlag's Tower, and it was a great dungeon crawl.
BG2: probably their most solid game. Carries over some problems (RTWP), adds new ones (the writing is... well, variable. Let's leave it at that and not go into the romances), but all in all I think it's good to very good, and I'm more tempted to push it towards the very due to the encounter design. I don't think I realized how good we had it with BG2 until I played everything that came after.
NWN1: I hated the game. It's the RTWP and empty maps and trash mobs of BG1, except we now have pre-3.5 3E, with all its idiocies, running on one of the clunkiest engines ever made ("DtU's was much worse" is about the only good thing I can say about Aurora), with a completely idiotic plot, rubbish encounter design, ugly graphics, just ugly everything. I don't care how good some of the modules are (and some are quite good), their running on such a clunky engine was enough to ruin most of them for me.
KOTOR: good god, this is it, the one that cemented the Bioware formula. There's the romances from BG2, the endless trash mobs from BG1, the same clunky engine as NWN1, except now we also have the TWEEST! which happens to be one of the worst-written, most predictable, most patronizing twists I have ever seen outside of M. Night Shyamalan (or however he spells it) movies. And one of the shittiest minigames ever (seriously, WHY did they even bother). Of course it's Star Wars AND it's Bioware so everyone loves it.
JE: a better KOTOR, mostly. Same engine, same story structure, same companion system, except it's shorter, the combat isn't any better but goes faster and so doesn't make you feel that running from province to province in Daggerfall would be a better use of your time, and while the setting is pure schlock at least it's not something we've seen hundreds of time before.
ME1: a better JE. It's actually the closest Bioware game to "average" that I can think of. Nothing in it is brilliant in any way, but nothing is really so incredibly bad that I'd rather play Oblivion (eat your heart out, Mako haters). The setting has plenty of idiocy (see DraQ posts above) but I can ignore it more easily.
ME2: let's take ME1, and instead of fixing its RPG aspects we'll rip them out entirely and replace them with a horrible, HORRIBLE corridor shooter. And then everyone will love it, even on the 'dex. Needless to say, I don't. Also, Human Reaper. And Collectors. And just about every single piece of writing related to the MQ.
ME3: huge improvement over ME2's shooting mechanics, mainly because you have more than one or two abilities to cycle through while patiently waiting for moles to pop. Plays like something in between ME1 and ME2. Story is one of the stupidest ever written for a computer game, and reaches magnificent (though entirely predictable, considering what came all the way back in ME2) heights at the finale.
DAO: better than NWN1, but still a shit game. Fake C&C by the truckloads, enough to fool even the hardest to please C&C fans. Absolutely horrendous combat system lifted straight out of WOW, and that could only be made worse by absolutely horrid encounter design that's perhaps even worse than NWN1's. Some cool set pieces. Completely and utterly retarded story set in Grimdark Fantasy Generica 101. The actual C&C that is there is good, the few (very, very few) not-trash-mobs fights would've been pretty cool if the spell system wasn't so broken, but none of this saves the game. This and NWN1 are the only 2 Bioware games I actually regret finishing.