I own a '96 318ti. I purchased mine for $7000 last spring which was fully loaded and had about 55k miles. There's also the sport model which has split leather/fabric interior, a slightly different body treatment (I think) and stiffer springs. The one big option I looked for and which seems to add considerable value is the california roof, but I only saw one when I test drove a new ti in '99.
I have mixed feelings about the car. I've owned several German cars: vw's, a porsche, audi, etc., but this is my first BMW. I wanted it because I really enjoyed test driving it in '99 but couldn't afford it since I'd just graduated from college. Since I don't have a big income, this was an affordable option for me. So, the benefits are the fit and finish, great bmw perks (e.g., blue tinted mirrors), but most of all, the way it drives. It's not quick, but it's definitely a car to be driven - it reminds me a little of my 944 - not too fast, but a great car to drive.
The downside is that even thought it was "cheap," it cost the same price to fix as other BMW's - e.g., my lock cylinder and housing just went and I'm looking at $600 for parts and labor - but this is true of most any higher quality european car.
I've put about 17k miles on in the last year, and have had few problems. I really enjoy driving it, and people can't believe I only paid $7k for it. You can find some on ebay for reasonable prices (that's where I got mine).
I do get teased from time to time that it's a "girl" car. You know what, I don't care - my friends that drive $7k dollar cars are behind the wheel of a 2 door civic - my other friends who have real nice bmw's are paying ridiculous payments, so I think I have the best of both worlds - just as long as nothing major goes wrong...