I still remember the first time I tried to make a sharp, tight, turn; the cockpit began to shutter just before the wings were ripped off the fuselage. Excellent flight mechanics made this game one of the most challenging and rewarding simulations ever. I'm only a casual sim player, but if you want depth in your flight mechanics and a realistic feel, this has it.
In terms of story, pacing, character development, gameplay, and complexity, nothing comes close to BG2. This is one of those games that I replay every once and a while to remind me of what an RPG for the PC should be. There is depth here in every aspect of gameplay, and a polish that you can only find from a development team who love what they are doing. This is one of the very best. Buy it. Play it. Love it.