You'll get plenty of opinions on this one. I've got some 4.5x14 scopes (Leupold and Burris), a 6x18 Leupold VX2, and a 6.5x20 VariX III (and a few others). For out to 400 or so, I'm good with any of them. Out past that, I've found that I like the BDC dots or lines. So if you want a usable scope for less than $500, I'd recommend the Burris FFII with the BDC dots. That's only $300. The Nikon 4x16 would be good, but I personally don't like their approach to the BDC dots. The Leupold 6x18 has turned out to be a good choice, and their BDC dots are about right. That Burris has been a great scope and it's the one that I first started using the BDC system on. Like I've said to folks, I didn't trust the dots. But...one day along came a big hog at 400 (per the rangefinder) and I put that specific dot on him and squeezed and down he went. Same thing later on a coyote at 400. So now I trust the dots.
And then there are the scopes with range adjustment turrets, but I'll stay out of that conversation.