Unfortunately, there is no uber-airline that's right for all circumstances.

Asking the question as, "I've got X MR points with AmEx, and want to go from MCO to BUD, returning from FCO this summer in biz or FC. What's the best airline, and how can I get award tickets on it using my AmEx miles?" would probably get you better answers to what I think you're trying to ask.

Unfortunately, there is no single best airline to Europe.

If you're looking at business class, then a lot of people will say CO is the best choice. On the other hand, CO doesn't have any FC to speak of. SR and BA are both great, and I'd take either one non-stop in FC any day over taking the other with a connection. In some cases, the airlines are close in quality, and the speicifc equipment being used on the route might push me in one direction or the other.

Without more details, it's really not possible to give you a good answer...