Originally Posted by
RobOnLI
This.
While TK is nice it's also the shortest long haul from PEK to Europe, leaving you with a longer "domestic" flight in Europe. Does that matter? Because the IST lounge will be the best of all of them, IMO.
Give us more data to work with. However, based on your initial question most here would rank them in this order: LX, LH, CA.
-RM
I'd put OS (which appears to serve PEK 5 days a week though is not on OP's list so may not be available) over LH as a solo passenger for the throne seat (if available). That and VIE is a really easy transfer airport (and I'm a big fan of OS food).