By far the Vapor VI has been the best in the series for my particular foot (long and narrow). It is by far the most stable and supportive tennis shoe I've found to date. The only downside is that the outsoles wear too quickly (herringbone pattern is not the best for hardcourt IMO). I still have three pairs of Vapor VI's and I stock up whenever I find them on the *bay in my size.
Vapor V's were very nice as well.
I'm curious to try Fed's new 2012 shoes . . .
wilson k90, babolat star 3