I'm a big fan of Stride Rite. They have both Pre-walkers (meant for babies who are crawling or have been walking less than 6 months) and Walkers.
I don't know what your budget is, but they are great quality, and get really high ratings as far as being safe for their feet (developing arches, etc etc).
Brendan has a pair of the Pre-walkers and while he only wears them when we go out places, he really likes them and they look cute too