Depends on your budget and what you prefer.
If got budget, I would get a Rodenstock filter. Costs about twice as much as a B+W MRC, but worth it if you want one of the best filters. Rodenstock is a company with a far longer history of manufacturing top-of-the-line optics than Schneider.
2nd choice?
I like the range of Nikon multi-coated filters, after that, any of the high-end filters like Hoya HD, Pro-1 digital, SHMC, B+W. Some folks in the US like Heliopan and Tiffen for high-end filters, but I've never tried them so I can't comment.
Note: IIRC, there have been some reports (here on CS) of Hoya HD's cracking or breaking. No dropping or fall, just crack from being screwed in or something like that.