www.pbase.com is a very popular one. You basically get 200MB for $23/year -- and their pricing structure allows scaling by 200MB increments on a month-to-month basis. However, their resized views do lose sharpness, ie. when you choose a smaller size than the original image.
If you need more than 200MB and/or need better resized views than pbase.com and don't expect too many hits, you might also consider www.smugmug.com. They charge $30/year for the basic service that provides 2GB/month bandwidth (w/ extra bandwidth for unusual months) or $50/year for power user service that provides 4GB/month. Storage is essentially unlimited, and people can also use their printing service, if desired.
Both have free trial periods to check out.
FWIW, I use pbase.com but I might also add an account w/ smugmug.com if I start turning my photography into a semi-profession for freelance work.