Up here in Canuckada the Elise is the same price as the Viper SRT-10. I'm looking at around $55,000 for either of them.
I'm not worried about fuel, my partner at work has an SRT-10 and he says it's actually not that bad on fuel, he's done a couple large road trips with it.
I rode bikes for 7 years, I had a 2000 Honda CBR600F4 for 4 years, I loved it. Then I sold it and bought a 2004 Yamaha R1 and rode it for 2 years. I really miss riding, but I just don't have enough self control for one. I've been looking at a Ducati 996 just for cruising around and trying not to die, but that'll be later.
I've had the NSX for two years now, I've had a lot of fun with it, I've raced it several times on different tracks. Now I either want a really light car like the Elise with incredible handling, or a big power car like the Viper. I'm mostly looking for something I don't have to modify to have fun with. I've done enough wrenching when I was a DSM (Eagle Talon) guy.
I'm still not sure what I want, one thing I really think will be important will be open top, either Targa or Convertible. Right now I'm leaning towards an SRT-10 just because I haven't had a really fast car since my heavily modified Talon.
From these cars you gave me I chose Lotus Elise because it's (the initial first gen model) affordable and should be fun to drive.
Viper SRT-10 could be an option if I had enough money to buy it and feed it with gas. And - a car with 8 liter gas engine is not for 21th century.
After all I would just buy a nice new motorcycle for this season. Way more fun and pleasure, way cheaper to buy and run and better to the environment (if you care about that stuff). Motorcycle is a device that converts gasoline into pure adrenalin and does it with 100% efficiently.
Why would you replace NSX?