As far as I remember at that time I hardly had any mods let alone for stability/performance, maybe cosmetic ones, nothing that could have caused crashes and I simply do not remember the game stability being this awful. The majority of the games I play have a couple of crashes if any at all, I consider this amount to be one of the worst I ever experienced actually. The second worst is DAO, but that is very specific, easily recreated crashing in Denerim, not like Oblivion, because in this game I can't replicate the crashing. Sometimes it's the loading screen, sometimes combat, sometimes running around exploring the map.

Wow, that really sucks. I've started playing Oblivion again in the last few days, and over the course of maybe ten hours of playing, thus far the only crash I've had was my own fault; in other words I know exactly what caused it and it wasn't anything specific to the game. I haven't had any random crashes at all. Now, it's possible that my version is simply a little more stable than what's on GOG; my install is from actual physical media rather than whatever the current release on GOG is, even though I have also purchased the GOTY version from here. (I don't plan to install the GOTY version until the next time I decide to start a new character)

I've had occasional crashes in DAO as well, and for me those ones have been random, but I'm lucky enough to have downloaded the installers before GOG added DAO to the Preservation Program and made updates that broke the game for a lot of players, so the crashes I have are related to issues that were never resolved in the past, rather than new issues GOG created by accident.