Don't you think that was an interesting experience for you?
Wouldn't you say that was a fun experience for you?
この場合、次のような言い方ができますよ。
ーDon't you think that was an interesting experience for you?
「あなたにとって興味深い(面白い)経験だったんじゃない?」
ーWouldn't you say that was a fun experience for you?
「あなたにとって楽しい(面白い)経験だったんじゃない?」
ご参考まで!