It would be a toss up between the new colbalt turbo and the neon. But I'd still say the neon will give more bang for the buck and has a proven platform.
I'd had both an srt4 and a bugeye wrx. Both modified. WRX got to 12.6@112 with a turbo upgrade in 40 degree weather. The srt4 got to 13.0@109 in 104 degree weather with stock turbo. Both were fun cars but unless you plan on upgrading the transmission on the bugeye, go srt4.
I had an 06 Cobalt SS/SC and I loved it. I only got rid of it to get the GTO. But that car is so much fun to drive. And I personally think they look hella better than the Neon. And yeah it may be turboed, but it's still a Neon.