In general Japanese cars are boring.... The IS is a bit of an exception in that it is one of the few RWD japanese cars. I bought an 01 IS when they first came out in the US... A friend of mine had an 01 330.... The IS was probably 90% as fun and handled very well compared to the BMW but of course was no BMW.... Of course once I left the dealer I never saw them again..... Not really the case for the BMW.

My brother has owned two preowned Audi's... A TT and A6... both were good cars but he visited the dealer way more than I thought should occur with cars that new. As with any car the dealer makes the biggest difference. I'd ask around and get some input on the local dealers.

My vote:
1) IS
2) Audi
3) something besides a Merc... I looked into an 07 C240 once.... I know its minor but.... they wanted $38 for an oil filter and $70 for an air filter..... If little things like that are soo expensive... I'd hate to see something major break...