I think filter choice depends on a couple of factors:

1. what and how you shoot (screw-ins vs. the "systems" approach, etc.), and

2. what you put them in front of.

Issue #1 can get rather complex, as it involves both physical practicality and convenience factors, along with optical quality issues. Add a good dose of philosophical sprinkles (e.g. to what extent should you "enhance" nature vs. simply overcoming limitations of the media's response) and you have your filter cake ready for display. Better brands of filters (B+W, etc.) are likely to be optically superior to the cheapies. Whether one is likely to see the difference is a separate question, which leads to issue #2.

While I haven't done any scientific testing, my guess is that putting a high-precision, optically perfect filter in front of a cheap lens is probably a waste of money. Thus, folks shooting with "consumer-grade" lenses can probably get by with Tiffen or other so-called second-tier brands, and never see any difference. Conversely, those using top-quality lenses will probably noticeably degrade image quality with less-precise glass filters. Similarly, with top-quality lenses, you're more likely to see the benefit of multi-coated filters.

Most of my glass filters are B+W, but I've also found Heliopan to be pretty good - especially for larger sizes (I have a couple of lenses that use 105mm filters - cough, choke). But, I also use resin, gel, and polyester filters for special effects (ND grads, IR, etc.). I really like the effect created by Zeiss Softars, so I think they are worth the expense, but I also use white and black netting for diffusion in certain situations.

Bottom line? I don't think there's a one-brand-fits-all magic filter bullet. It depends too much on personal preferences and style. Oh, and budget may play a role, too.