I thought that as far as structure was concerned, the Sekiei League tournament was one of the better ones in the sense that the changing battlefields was a clever idea that tested each trainer's ability to adapt. But in terms of the battles themselves, the writers could've done a lot better. My biggest gripe [other than how Satoshi lost] was that many of the Pokemon used in the later rounds were base stage Pokemon, such as Onisuzume and Menokurage in Hiroshi's battle against Sayuri.
If we exclude Ash VS Ritchie, the Kanto League is decently good, at least considering it was the first league. The only problem I had was that TRio had too much screen time, which is noticeable when we had 2 battle halves in the same episode