Our leader, Frank Diabolu, has been doing a bunch of top 10 cover galleries lately, so here's my contribution.
If the only comics you read are soap operas about gaily apparelled muscle-men, then you're really missing out. Sheldon Mayer was one of the most talented people to ever work for DC, but since he didn't do a lot of super-hero comics, you've probably never heard of him. I'm too lazy to do an in-depth article about him. I'm sure Wikipedia does a good job. Instead, here are the covers from his longest running comics series, Sugar & Spike, which lasted 98 issues from 1956-1971. Start here and then click on the next issue link.