I bet this was already documented already but I'll say it.

I got lucky and managed to beat the game on "normal" mode and wanted the challenge and started again in hardcoe mode.

My game freezes:

1. Black Mountain with the Nightkin and/or Super Mutants starting a fight
2. Helios One with the Automated Turrent Guns
3. Gun Runners HQ while using a stealth boy
4. Sunset Sasaparailla HQ attacking a robot with and without VATS
5. Basically any combat situation using VATS

Come on, Bethesda, get your act together and fix all the bugs you let those Obsidian slackers create.