Generally, most digital photo frames will work well ... but, the better, more known brands cost more money (relative to their features, of course). You should be fine with any digital photo frame, so go to your local electronics store and you should find something suitable for less than 100 dollars.
My one suggestion is to find a digital photo frame that supports memory cards. Units which support memory cards are a lot easier to use - you can even take the memory card right out of the camera and stick it into the digital photo frame to view photos instantly. Frames which do not support memory cards require using your computer to load pictures, which is a bit more time consuming. Also, these frames generally have far less memory available than the average memory card, meaning they won't hold as many pictures as possible. Memory cards themselves are cheap, so you could always get an additional memory card for your digital photo player, and if you shop around, both the frame and the memory card would still cost less than 100 dollars.
The link below lists several digital photo frames available from Circuit City; many should be suitable for you, so feel free to have a look at them. I hope this helps!