My best four current logos from each of the "major" sports - photos only - I didn't include the MLS even though one of their owners is very optimistic. Logos are in no particular order.
MLB (logo, NOT cap design)
Yankees are just a classic logo to me as is the Dodgers. Everything looks better in a circle it seems, as Oakland can attest to. The Rockies just resonates with me and even though I'm not a Mets fan, the skyline in the background is big league.
NFL (logo ON the helmet)
The Ravens is just a bad ass looking helmet and how can you not love the Buccaneers, there's a pirate on it! The Bengals is designed like the animal, the Chargers is simple yet effective, and how can you argue with the Silver & Black of the Raiders?
So glad the Islanders went back to this and got rid of the fisherman. Oil dripping on the Oilers logo and the simplicity of the Canadiens (the "H" is for "Hockey", not "Habs"). The Sabres incorporated sabres and Buffalo and made it work while the musical Blues logo works, even though it is pretty silly.
The Pacers logo is simple and letter-based while the new-school Thunder logo simply looks sharp. The Rockets logo looks like a rocket taking off and how can you not think of #23 when you see the Bulls logo? Back again to the "everything looks good in a circle" when you look at the Warriors new logo.
I'm tired, time for some zzz's.