Hm... Personally, I consider this arbitrary in the sense that there is no clear definition of RPG, which makes it kind of difficult to argue.
Since the question is which is the best RPGmaker, I would answer BioWare with ease, simply because my definition of RPG does not simply mean character customisation in an open world where your actions barely has consequence, except for a rumors and gossip. To me, it means the interaction between characters and with the world in a sense that leaves a mark. Since the characters are pretty... poor in Bethesda's games, I can't really consider them very good from a RPG standpoint. Since in Square Enix games you generally don't control your character's actions in dialogue, I don't really consider them very RPGish either. Please note that I am not saying these are bad games! Many are really good games, that I have enjoyed thoroughly, though not so much as a RPG, as for the other merits they have.
Shortly following on that, I'll show myself as a heathen by admitting to having played neither Bauldur's Gate game. However, I still have enjoyed pretty much all of their games that I have played. I recently completed DA2 and completed ME2 a long time ago, and I do not really see the reason for the hate they receive, personally finding them superior in almost every way compared to their predecessor. Removing RPG elements? Which? I can't say much for ME2, seeing how long ago it was, but I found that DA2's roleplaying opportunities were greater than those of Origin's (also love the story and the conflicts of the game). Just curious, do you mean that you cannot customize your character in as many ways (races, classes and such), or what? The absolutely largest fault of any BioWare game is definitely its replayability value. Oblivion's open world and FFVII's really long storyline leaves for hours and hours of gameplay, while DA:O is over in only a couple of hours. Haven't yet replayed DA2, but it would seem in hindsight that your choices might not matter so much (meaning that I don't really know what is the case, but got that feeling). I also got really immersed in DA2 for some reason, don't really know what pulled me in.
Don't have much experience of Square (Enix) games, having only played a few (Chrono Trigger, a few FF games, sadly not KH though I have been intrigued by them for some time), but they seem to have some high quality games when you feel for simply immersing yourself in a world where you simply follow what is happening and don't decide more than which attack to use.
Bethesda has made som really good games (sadly never got into Morrowind, it never really hooked onto me), but their open worlds generally do not fit my play style very well (i.e. they are fun to play at times, but not what I usually look for). Personally I wasn't as fond of FO3 as New Vegas, simply because it felt a step away from the Fallout setting. The funny thing is that FO3 was the first FO game I played. (I played them in order 3 - 1 - 2 - NV).
EDIT (big one apparently):
I have read all the posts in the thread and read about people who have well thought-through plans for their characters in games like Oblivion (I'll use it as example from now on), giving their character flaws and wishes, change of opinion due something and so on. I really admire you, but I have never been able to do that in Oblivion, never got that immersion since it felt as if the world didn't really respond to my acts. Part of it is that the game didn't reward me for the act, but that is kind of a weak argument.
Also, I have a dislike for the level-scaling system, which almost requires you to make a character with at least a sensible set up of character skills (for example a character with Alchemy as Major Skill is pretty doomed... unless he doesn't use Alchemy, that is). I tried to make a mage with the Atronach birthsign (meaning he doesn't regenerate magick on his own), and that was fun for a while but I was too sparing with my resources (barely ever used Welkynd stones, for example), so he ended up being a pretty... flat character (very much my own fault).
If I had the wish and the... 'discipline' to make a character where I bar ways for my character (for example, a mage that adhers to laws wouldn't commit a crime, complete a quest that resorts to crime or choose a path that in some way involes crime, even if it would've been easier), I believe it would have spurred my interest in the game, but the time I've already spent playing the game would probably spoil that experience.
Also... on an unrelated note, would someone please point out the RPG elements that had been cut-out in ME2 and DA2?
(Geez, that edit became way larger than originally intended.)
