I'd have to say rear, but to be honest I'm saying that for the wrong reasons
Rear is more fun
Well, that and it, to me at least is more predictable, rear wheel drive tends to be found on "driver's cars", that is they're set up better to feel the road and available traction, and when it goes wrong you know exactly what's going to happen and when (ie. fishtailing when you power on too early/hard). Front seems "safer" but also less predictable, front drive doesn't seem to give the road feel (whether that's an inherent thing about front wheel drive, or more down to suspension set up typically found on FWD cars, I don't know). Also FWD typically results in understeer which I find harder to instinctively deal with than oversteer.