I use sandals constantly and year around. Merrels are good, as are Teva, The North Face, La Sportiva and some others, but the ones that I have found to be the longest lasting and still good for hiking are the Chacos. They're pricey, but worth it and they have a great warranty (I cracked an old pair in half and they replaced them for free). Plus they can be resoled, rewebbed, etc. if you don't like to give up old comfortable shoes.
Typically I buy a new pair of sandals before each new spring climbing season (I usually get them at the end of the summer to save money on the closeouts) and wear them most of the year. My current Chacos are on their their 3rd year (of nearly daily wear) without being replaced and still look really good. They also don't get all stinky like my sandals from Teva, The North Face and Merrel do, and I don't have particularly offensive feet normally. They take a little time to break in, but then they fit like a glove and are good to go.