This is a hard question as you've already got most of the best cars on the market
In addition to the italics above;
-New M5
-Ultima GTR spyder, they call it a "can am" (pretty sure they're still available in Aus, we have one at work thats aus delivered which is a 5.7L with an HKS turbo hanging off the side)
-The latest sl from merc, SL55's or SL63's arent too badly priced, although some members may have those already
-997 Turbo/Cab, would be nice to have a droptop porka floating around. Didnt you have a Turbo a while back?
-Dodge Viper, if there's someone bringing them in
-Would love to see a 997 GT2 but its a bit pricey, unless maybe an Aston gets sold...
-GT3 RS. Great addition to the white one and rare as hens teeth but not too expensive
-Ferrari California. I think its quite ugly personally but as its the new Italian on the block maybe the members would like it
-E55 AMG. Along the same lines as the white Masa
Thats all i can think of