Not much can compete with those cars!
I take it you want a manual transmission, yes? Hence not mentioning any Mercedes.
I think you'd probably be happy with a BMW 540i as well as the other cars you mentioned. Just drive it before the M5.

I think the Acura TL is a hot car and the new IS300 is very nice, too. They're both very "grown up."
BTW, congrats on #2!
