After a long haitus of Skyrim, I decided to come back to it yesterday. After about an hour of play I realized how much I missed mods, so I downloaded a bunch of new mods for it(inc. ERSO), played ~6 hours, then decided I didn't really like ERSO and decided to give SkyRe a try instead. After installing SkyRe I started encountering a consistant CTD whenever I launched the game just after the Bethesda Softworks screen; oh well, it was worth trying.

I uninstalled SkyRe and started to play without ERSO or SkyRe, but still got the CTD. Odd. I then tried uninstalling ALL my mods, and still got the CTD. Figuring I screwed up some core file earlier when installing SkyRe, I decided to to a completely clean install of Skyrim, but that didn't help either; with a new, clean installation of Skyrim, I'm still getting a CTD, even though yesterday I was playing both the clean version and a version with mods just fine.

TL;DR: After botching a mod install and running into a CTD, I did a clean install of Skyrim with no mods whatsoever, but I'm still getting the CTD. Can anyone help me with getting the core, unmodded game running again?

A crash at start often indicates a missing/disabled master file (*.esm). Check the list in Data Files to make sure they're all ticked.

Did you delete any folders/files left on the hard drive before reinstalling Skyrim ?

Ah, that was it. It seems I was a bit too overzealous in my mod-disabling.