I was tempted to start one of these threads myself...
a site that almost exclusively sells "betta" tanks. worst offenses include a .6 gal that's impossibly thin, one filled with jagged glass gravel, and a clock. also, all of these recommend feeding only a few times a week. And I think the site filtered out a negative review I posted.
edit: seems I forgot to mention the triple betta keeper...with clear dividers. Looks to be about a gallon..maybe 1.5.