My preference for the Skylines (sorry to thread-jack OP ;) ) :

1. R32
2. R34
3. R31 (lot of ppl go "WTF"... but see them with the right kit and damn theyre nice looking :D )
4. R33

Thats mainly on looks tho... engine wise etc, long as they have a RB26DETT you cant go wrong...but the 34 does have great handling etc over the older models. The R33 is too bloated for my liking...in saying that, I wouldnt say no to one but yeah...