I'd really like to forget about Welcome to the NHK and be excited and everything because it's got all those recommendations... but I found it so boring I wanted to cry... I made it through 18 eps because I was hoping the plot would start after all... but it still didn't... I'd like to forget - and get my wasted ratio back!
Shows I rewatched for at least two times without regretting or having to forget: Midori no Hibi, Claymore, Elfen Lied, Black Lagoon, Gunslinger Girl, Fullmetal Alchemist (first season), Shingetsutan Tsukihime, Shojo Kakumei Utena
Those good shows all have in common that you don't need to forget about having seen them and still discover something you didn't notice when you first watched