Here is my pat answer for this.
Trying to tell you everything you could consider is nigh impossible because there is so much out there. At $50 and under there are a lot of fine products and there's also a lot of junk. Knives are so subjective it's tough...
But if you want something nice in the mid price range that won't break the bank, my two standing reccomendations are:
The Spyderco Delica, Native or Endura - the new models especially are nice, and you can get a real good deal on the Native at Wally World of all places. It's normally $65, Wally World has it for $40. The reason I reccommend these three is that most people find their hands fit one of the three very comfortably. I'm an Endura person myself.
Something in the Benchmade Griptilian Series - 550 or 551. These are also real good knives, they're just different. I always list them because people tend to be Spyderco people or Benchmade people.
I'm no kind of expert but I like knives too, and I went through a lot of them before I found the one that made me happy. I wish I'd started with one of these models, because even if you move on it's handy to have a spare for the car, office, etc.