My pick would be the 2.5-10x40 Weaver Tactical. It not only has a Mildot, but the turrets are also in Mils. $300 from Midway. This scope is good enough for a regular gun, just in case you want to move it over one of these days.
Even for .22LR I do not go cheap. On one my my .22's I have a ACOG on it, for another I have an Aimpoint. On the flip side though, I have a Millet on my Bushmaster .450 :-(