Are you looking for something cute or something practical? I LOVE Loki's Easy Walk harness. It goes over his head and then straps under the belly. You attach the leash in the front (on the chest) so it discourages pulling. I find that I can still put sweatshirts on him because the clip peeks out just enough. It's super easy because it's only one clip - no arm holes to wrestle with. When Loki grew out of the smallest size, and was too small for the next size up, I actually called the company and they MADE him a custom sized one for $2 more. I love Premier.
http://www.premier.com/pages.cfm?id=74