The N54 335i and 535i (and xi) models are pretty stout..
This... 07-10 335i with the n54 twin turbo. Will make 400+whp with bolt ons, handle AMAZING, and are pretty easy to work on.
The "reliability" issues are fully documented by now and actually are not bad at all for anyone who can turn a wrench.
Icing on the cake is a 2008 335i with 70k miles or so can be had for $10-12k.
Amazing deal.