In addition to the Nikon Buckmaster 6-18x40 that others have mentioned (and that I like very much), here are a couple more budget options:
BSA Tactical Mil-Dot Rifle Scope 30mm Tube 6-24x 44mm Side Focus Glass
Most people scoff at BSA scopes, but this one is pretty good for the money. I have one on my 22-250 and I really like it. For a varmint rifle, it works very well. The people who laugh at it haven't used one.
SWFA SS 12x42 Tactical Riflescope
These scopes can me had in mil-mil or mil-moa configuration in 6x, 10x, 12x, 16x, and 20x. I have a 10x mil-moa model on my F-T/R rifle. It is rugged and repeatable, with OK glass. For daylight to early twilight use, it works very well. Higher end scopes with better glass will outperform it in low light. I don't see that as an issue for varminting use, though.
I'm sure someone will be along shortly to tell you to put a Nightforce on your .17HMR. Whatever.