I've seen many military aerobatic display teams over the years from the Thunderbirds to the Black Arrows performing their famous formation loop and barrel roll with 22 Hunters during the 1958 Farnborough Display. This is still a world record.

One team I have never seen are the Canadian Snowbirds. All are excellent in their own way although I'm not sure they always have the most suitable aircraft. I once saw a team trying to do formation aerobatics in F-104 Starfighters on full A/B. Impressive - yes, noisy - certainly, but entertainment? - NO. They were out of sight of the crowd for most of the display. The Patrouille de France always perform well & the Frecce Tricolori regularly put on the most impressive & original display sequence I've ever seen before their unfortunate accident.
Being a Brit I would have to go with the Reds for consistency, skill & sheer entertainment value. I've seen them many times but they still impress me.