I don't think of ecchi anime any differently than all of the rest. I just enjoy anime in general. But some of the series that is considered ecchi that I've seen are:

Love Hina
Grenadier
Cutie Honey
Da Capo
Chobits
Air Gear
Great Teacher Onizuka
Yumeria
Vandread
Tenjou Tenge
Onegai Teacher
Maho Sensei Negima
Ranma 1/2

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