The Z4M would be my choice, cause it has that deliciously revvy 3.2L Inline Six from the 'old' M3, and a nice tight chassis (not from personal experience). It looks pretty special too. At last, a nice little sports car from BMW with some cred (in this decade).
The Cayman doesnt do a whole lot for me - obviously you couldnt fault its drive, but the 911 and Boxter for me are more desirable. The little niche they've tried to put the Cayman in means it's come out too comprimised.
The TVR....it looks great, obviously offers the most thrills.....but I can't get around the rep they have for quality unfortunately......and Hammond says the interior smells like a Fibreglass Canoe Factory
I am a New Zealander, and I hate Greg Murphy. Yes, we exist.