Some interesting views here.
I have an R32 GTR with 470BHP that I have used on the road for the last 6 years, but never as a daily driver, it is too fierce and also too pretty!!
Maintenance wise, both me & my son are hands on so it has never cost us a lot, even the engine swop to a later lump was done by us! Even at that power it returns around 28 on a run and low 20's around town.
I have not come across a road car that is anywhere near as much fun.
Jacquie, my wife has also had an R33 GTS-t as a daily driver, this was 2.5 6 Cylinder turbo & RWD. This was good fun and not bad on fuel. Arse out action all day long
I have to say that for a day to day runaround with power when you need it, you are not going to go far wrong with a high spec Turbo diesel from either Audi or VW (and some others I can think of)
Like Sandy, I have been in Company car comfort for a few years and the best ones I have had were: X Type Diesel, Accord 2.2 Diesel Sport, Golf GT TDi, all giving good performance with 45 mpg. Couple this with long service intervals and it becomes an attractive option.
If I could get my good lady to part with her S Type Jag, I would definitely get her into a diesel, mind you the Jag is a 3.0 V6 yet still returns 32mpg on runs to the lake district (about 15 around town

)
Personally, I would struggle with a Scooby or Evo, whilst I know they are bags of fun they are bloody thirsty compared to the GTR
I would go for a Monaro, or VXR8, I have had one as a rental car in the US (called Pontiac G8) and it was superb, but you can get it as a 3.9 V6 over there. This doesn't really fit the budget though.
For the budget I think I would go for an Audi A6 or A8 with a big TDi or a Skyline R33 GTS-t or Skyline R34 GTT (both these are 2.5 turbo & RWD)
Anyway, ignore me. I have just bought an Aston Martin DB7 as my 'daily driver' but I am only here one week in every 5
Cheers
Kev