Go with
IrfanView. It's a very fast image viewer & browser for a
huge array of image formats, including Jpegs of course.
Personally I use
ACDSee to view/manage images, but it's not free & a lot of people prefer IrfanView anyway.
By the way, if you're only after opening a few pictures every now & then, well, no need to download software as Internet Explorer opens jpe's just fine.