I use filters for storage, as it keeps dust off of the front element. I try to remember to take them off before I go out shooting, especially if I'm shooting at night. That was an issue on my Canon (cheap Tiffen filter), and while the Hoya's I have a bit better, I do prefer no filter, though I'll probably look into a nice CPL and some ND filters. Eventually. I use hoods whenever possible, as my 135/2.8 has a built-in and the 28-70 has one that works well. The 40/1.8 doesn't have a hood, but it has a tiny front element so I'm not too afraid. Of course, I'm gonna have to find one for the new 58mm. That'll be fun...
Random thread contribution for today:_DSC9341
Just got a Minolta 58mm f/1.2 (mentioned above) this afternoon so I took it out and shot a bit after work. The above shot is at f/2, ISO 100, 1/8000 sec.
It's a great lens. Extremely fast, solid, but not too bulky, very sharp above f/2, with lovely bokeh and contrast. The coating is also excellent, as it barely flares, especially when compared to my Konica AR, and I really like the Minolta colors.