My 20sen.
I have a 28-year old 735i, and the reason i bought it was because its the car I grew up thinking "One day I'll drive that". It has a lot of emotional appeal, more so than a modern car. Old BMWs really had a natural character and attitude about them, unlike modern-day ones which are too lifestyle-ish (along with Audis). Sean Connery vs. Pierce Brosnan, if you like.
My daily driver is a Mk6 GTi. It took me the better part of 4 months of weekend test drives to decide. I was in no rush, as the test drives are much like dating (once you buy, you're married and cannot change). I started with the golf and naturally felt it was small, and too perky. Then tried just about everything in the RM200 to 250k range and even beyond. From what I could remember, here were my thoughts:
1. BMW 323i - nice car, but a bit breathless. Perhaps my next-in-line choice would have been this
2. 325i sport. A bit of a letdown because I had high hopes for this one. crap suspension and not that much faster than a 323i
3. Audi A4 - very well-built, but the 1.8t is a snail. the 2.0t wasn't out at the time
4. Passat - very well specced and finished, but the aluminum trim caused terrible sunlight glare. rotten luck with my seating position i guess
5. C230 V6 - nice car, nice engine, but felt tinny and not very solid
As I was leaving the Passat test drive, the dealer urged me to have another go at the golf. If you really know how to drive this car, it tugs at your heartstrings. Yes it's good in a straight line, its even better in corners. Very different to a rear-drive beemer, and needs a bit more care, but infinitely adjustable on the limit. More than its performance figures, its devastatingly quick as a point-to-point car. Fast comes very naturally to the GTi. Until you regularly drive one, you'll never really appreciate this quality.
Its been about a year now, and the car has done 25k km, hasn't skipped a beat and runs beautifully. The speedo is a bit optimistic (hit 248kmh yesterday), and the tyres and exhaust can rumble tiringly on a highway. Its boot is small, and its rubbish for family trips, but as your personal daily transport, it does a fine job.
Perhaps my only regret was not coming across an E90 335i in time
Hope this helps