I have used SMC, Nexland, and Linksys routers. They all worked more-or-less ok (occasional crashes and lockups, missing firmware features, etc.)
I bought a Xincom 503 (XC-DPG503) dual-wan router about a month ago. So far, I have had no crashes, restarts, or lockups. The firmware is excellent with very few missing features. One thing that I wish Xincom would add is PPTP VPN in addition to IPSEC. I sent Xincom a (fairly small) list of suggested firmware improvements - lets see if they respond.
Of course, if you don't have two wan connections you probably don't this router.
Mike