IMHO if we are comparing direct model line ups from years of production (i.e. not taking the 2004 Crossfire and comparing to the much better looking 2011 TT), the Crossfire trumps all in the looks department between 2004 - 2006 (biased opinion here of course).

But the new TT, Boxster, and Z all give the Crossfire a run for its money of course. Especially the new TT-S. That said, it is a testament to the Crossfire's timeless styling that people come up to me and ask me if my SRT-6 is new.

Performance wise the Boxster takes the cake, but the SRT-6 can hold its own in that category. SLK should run about even with the Crossfire (maybe slightly below if you are comparing it to a Crossfire Coupe), and the 2004-2006 TT I don't think really would hold a flame to any of these models during that time period.