Great hang-out spots in Ikebukuro?

I will be in Japan for about 3 weeks in the Ikebukuro area. Any recommendations for relaxing, dinning, and just having a great time after sight seeing?

Lumine Ikebukuro restaurant floors are a good place to check out for food, including several good-value buffet restaurants: http://www.bento.com/ra-ike.html

Sunshine Aquarium is open until 8pm: http://whereintokyo.com/venues/25126.html It's next to Alpa shopping mall, which has more restaurants, reasonably priced shopping, a wine bar or two, and other attractions.

Vivo is a nice beer bar with good craft beers from the US and Japan: http://www.bento.com/rev/2332.html

Nekorobi is interesting if you've never been to a cat cafe before: http://whereintokyo.com/venues/25010.html

Thank you so much! This definitely helps!