Sure, if money were no object, I get the DA 200mm f/2.8 ($856 on Amazon) or the DA 50-135mm f/2.8 ($708).
I've been using a Hanimex 200mm f/3.5 with uneven results:
Flickr: My stuff tagged with Hanimex 200mm f/3.5
Some examples:
200mm worked ok here:
But was a little tight here (and was hard to MF when they were moving around more)
Also, 200 mm is too tight if sitting on the sidelines of a gymnasium for kids' sports.
First preference would be a fast auto-focus zoom in the (approximately) 50-250 range for under $400. Does such a thing exist?
Second preference would be a manual-focus zoom.
Third - a shorter (maybe 100-150mm?) fast prime.
Any suggestions?