I agree - bang for your buck, the mustang is hard to beat. -I think one guy on BITOG got better mileage with his 2011 mustang than (the family car), Accord.
Its also much more practical relative to the older mustangs size wise, you can fit a great deal more into the car and there is more cabin space as well -My 2001 mustang was a tight fit.
Going into fall, you might get a tempting deal on a new 2011 as they start to clear out inventory. -I've never bought new, but when you see what some people are asking for their -USED car- it makes me wonder...
Miata is a very well balanced fun car -about as practical as a $2 bill.
G35 - GREAT car I test drove a few (sedan w MANUAL ). HOWEVER its work to find a manual and the owners KNOW that is the transmission everyone wants...
Honda CRZ - I am going to disagree with the majority here. I WOULD ALSO BET THEY NEVER DROVE ONE.
It is fun to drive -reminds me of my old Acura Integra. No its not a race car, but its not meant to be -its nimble -Like a Mini Cooper. FUN. (and frugal)
Hyundai coupe - Have not driven one. No comment.
350z - Decent but flawed. 370z is an improvement in every way. in a slighty more snug package.
ALL in all YOU should drive all of them and make a judgment call from there. The peanut gallery will not be driving the car you will.
-I personally look for all the cars I want, then buy based on what car stands out as a GREAT VALUE. -This does not mean cheap, but rather what I get at a certain price. Last year, I bought a Mazda Protege5 with 30,000miles for $5,000 even. I had a list of about ten cars and that one in particular was not very high on the list. But when car with 30K miles pops up on Craigslist for only $5K (and the car checks out ok of course!) Its hard to pass up...