My E34, a 1990 535i 5-speed. The M30 engine is in my opinion one of the best on the road provided you don't let it run hot because they are known for blowing head gaskets when run hot. I bought this car in 2001 the weekend before 9/11 from a guy in Raleigh via Ebay.
It has been the best car I've ever owned only being in the shop twice since I've owned it. First for something I could probably have done DIY, but it was so frigging cold and I don't have an enclosed garage to replace a broken ignition switch lock and front wheel hub/bearings. The second time it was in the shop was a little pricier at around $700 for new struts and front end suspension bushings which I didn't feel like I was experienced enough, nor did I have the proper tools to do the job safely.
In the time I've owned the car I've replaced the radiator, starter, and water pump all DIY. That's it other than normal maintenance.
I can't tell you how nice it has been to not have had a car payment since, well since so far back I can' remember because I paid $7K cash for this.
It's closing in on a quarter million miles now and as far as I'm concerned it might be the last car I'll ever own.
There is an E34 for sale in the Flea Market right now, but it looks a little ragged out from what I can see in the photos, and proper maintenance is everything to the lifespan of these cars. I absolutely would not buy one without a complete verifiable maintenance history, but if you can find one that has been well cared for, then I'd jump on it in a heartbeat.