The older Tasco scopes were good for the money, I've used/had a several that never gave me any problems. My cousin has an older Tasco 4x32 on his Marlin 336 30-30 that's been on the gun since it was new. The gun is at least 15 years old, bought used, as his first deer rifle. It's never gotten out of zero one time, and it's bright enough for shots at dusk too. I can't say that about the newer ones.
The less expensive Bushnell models give outstanding performance for the money. The Banners and the Trophy's are great scopes, and I had an old Sportview 3-9x40 on several different guns with no issues. I ended up selling it to my buddy for him to put on his new T/C Thunderhawk (that gives an idea of how long ago I sold it) and he still uses it to this day.
I've also had a lot of performance out of the Simmons line as well. Several Whitetail Classics (it wasn't a cheap scope), Whitetails, Pro-Hunters, Deerfields, all have passed through my hands with no issues or complaints.
If you're going to buy a cheaper scope (under $75-$100), keep it simple. No fancy do-dads and such. Preferably a fixed power.
There's a guy on AuctionArms.com right now that's got several Simmons Whitetail Classic 4x32 scopes for $69 each, new old stock. That's a good deal on a good scope. When the Classic was the top of the Simmons line, I think that the retail on those scopes was something like $140 or so. I can remember my old Cabela's catalog listing the 2.5-8x36 Classic for $189.99, and the 3.5-10x40 was $199.99. If you can find them, these scopes are usually good deals for the $$. They pop up with some regularity on ebay, both new and used.
Now, I'll stop rambling and say that if you want to keep it under $100 for a new scope that's easy to find, you aren't going to get a better scope than the Bushnell Banner or Trophy.