I can't fathom a reason for "several hundred tabs" unless your job specifically requires you to open that number of tabs for some (albeit strange) reason.
The unfinished reading weighs me down every day, but I keep them open anyway. Some days I get productive and read a half dozen tabs, but never anything substantial. It's an embarrassing "problem."
Awesome / useless plugin idea: an artificial time bomb that removes the tab and all traces of the website from your history after being open longer than some period of time (e.g. one week). Obviously a bookmark circumvents this dilemma, but the problem itself isn't rational to begin with.