I think leather looks the best. Cloth is an option on almost all models in Europe...I have seen a 740iL and an S500 with cloth interior...shocking :-0
My cousin just got a 325i with leatherette. She thought it was leather, and didn't realize until after she bought it (not the sharpest tool in the shed). She does like it now. It does look like leather (kind of), but it feels a bit more "spongy", and you do not slide across it as easy. It is known to be quite durable, like Mercedes' MB-Tex.
Bottom line...get leather. With just a once or twice a year clean/conditioning, it will last years and years...and be better for resale value!!