mechmouse: But the Baldars Gate example are mostly bugs rather than using a spell outside of very narrow parameters.
Until games are entirely physics and AI based, it requires a programmer to code for each spell effect on evey in game item.
Actually, I see them as unusual side effects of the way the game was designed and coded.
1. The polymorphed form's weapons are treated as magically created weapons (except that the message when you try to unequip your weapon is different), and the game was only coded to allow one magically created weapon per character. Hence, casting another spell overwrites the first one, which can cause rather silly effects. (Wolf shooting a sling, for example.)
2. How else, other than denying the teleport, could the game have handled it? (If your suggestion is to push others out of the way, that could in turn be used to force NPCs out of the way, and what if there's not enough room anyway?)
3. The backstab with Iron Giant fists could legitimately be considered a bug, but it is fun to do this sort of thing.
4. Killing enemies without lowering their HP to 0 is clearly intended for this form. The only possible bug is not giving essential NPCs immunity to stat drain.
Hence, 1 and 2 would have been tricker to program differently (and exploits with 2 likely would have been possible anyway), 3 isn't a major game breaker, and 4 is intended (though the ability to softlock the game could be considered a bug).
Anyway, I can reiterate my recommendation of Morrowind, which is probably the best Elder Scrolls game for what you are looking for.
Arena and Daggerfall are a bit too simple in their engines.
Oblivion omits some of the cool spell effects (Levitate and Jump, for example), although it has the advantage of actually using a physics engine, so examples similar to what you mentioned may actually be possible. (I haven't played Oblivion, however.)
Skyrim (which I haven't played either) took out the spellmaker entirely, further limiting what you can do with magic.
thejimz: It still isn't a proper real-time game. The 6-second system during combat heavily limits what you can do during a turn. No matter how many attack animations you have, it isn't possible to hit more than X number of times (based on your attacks per turn) during a 6 second period. Plus, spells don't go off whenever you want: you have to wait until a turn comes around before you can start casting. If your spell is interrupted, you have to wait for another turn again. These are all turn-based mechanics, despite the pseudo-real-time trappings.
All of the counterexamples you mentioned occur because everyone's turn happens simultaneously. I'll give you that it's not a traditional turn-based system--it's somewhat along the lines of a "simultaneous execution" TBS, like Laser Squad Nemesis or Lethal Tactics. But, whatever you want to call it, BG2 definitely is not a real-time game. Every individual character has to deal with turns.
Thing is, other games that nobody considers turn-based have features like that. In Castlevania, for example, you can't swing your whip again until the animation from your first whip finishes, and there is a limit on the number of projectiles you can have on the screen at once. Also, when you are using your whip, you can't move (though if you are already in mid-air, you will still continue on your current trajectory.
Also, with spell casting in the Infinity Engine, you can actually start to cast a spell at any time, provided that you haven't started to cast a spell in the last 6 seconds. Furthermore, having started casting a spell in the last 6 seconds does not prevent you from making physical attacks or moving. In addition, Throne of Bhaal added a spell (Improved Alacrity) that temporarily gets rid of the limitation, allowing you to throw spells as fast as you can cast them. The one exception is not being able to do anything else during the casting animation, but that's no different from (in the Castlevania example) being unable to do anything else while swinging your whip.
As a side note, the same cast-and-attack behavior is seen in Dungeon Hack.