NAPA Gold for a daily driver. I used a System One trash can - the same one - for many years, on the race stuff. Clean it, check it after every weekend. Change the o-rings occasionally. I think it was 45 micron. I loved it. I really like the Clear View Filtration assemblies being sold now. That would be my choice.

I see a lot K&Ns on fuel and professional engines. Don't know the number, I expect at that level, people are having filters made to their spec.

Micron rating needs to be paid attention to. The Wix 51515R and 57003R are 61 micron. Standard Wix is 19. The Fram HP6A is 12. I see street filters down around 10.

I suggest reading the David Reher article referenced in the engine oil thread.