the acura is most likely the best deal for the money.
the g35 has a really good engine
the audi is awesome,but gets really expensive to fix
the caddy has a big strong v-8.
there are a few things i consider when i purchase a car.
4.fun to drive
check out carreviews.com, sort like glocktalk for cars.....
personally i would go w/the acura,
i have been driving honda products for ever and they are hard to beat,
good luck, lets us know how you do.