For $100 you should definitely look at porro or reverse-porro design.
I liked the the Vortex Vanquish, but for me the eye cups were too small and the feeling of my eyelashes touching the inside of the eye cups bothered me. The image quality was very good for $80 binos though, and they are light and compact.
Also consider the midsize Kowa YF II, Opticron Savanna, Vortex Raptor, and Leupold Yosemite (discontinued). I believe they're all produced by the same factory, though there are differences. This would be a nice compromise between size, cost, and image quality.