Firefox

Personally, I have a window with

-Pictures that lead to sites I want to keep up with
-2 manga sites
-A tracker for streams
-2 sites for looking up information for games i'm playing

And a second window with
-A series i'm keeping up with
-2 spreadsheet trackers for games
-a dozen or so youtube pages, most of which are music I want to alternate looping

I feel like it's just one of those things that once you get used to doing, you generally always have a lot of tabs open.