There's always an official patch and an unofficial patch for Bethesda games from what i've seen. People seem to use one or the other. Is it a no-no to use both of them at the same time? I have Morrowind, Oblivion and Fallout 3 for the pc, and i'm asking this as a general question regarding all 3, including any patches for the expansions as well. Are some better than others?

Well, I can't speak about Oblivion or FO3 because this isn't the proper forum for them, but the Morrowind patches are different from each other and they don't conflict. The MPP is a master file (.esm) that fixes various issues that were never addressed by Bethesda while the actual patches affect the morrowind.exe file. The Morrowind Code Patch also addresses various issues Bethesda never touched, but it is completely different from the MPP and neither conflict with each other.

Make sure to install morrowind's official patch first; both the patch project and code patch are made for the latest official version.

When I used Oblivion's patch over a year ago, the unofficial patch was to be applied after the latest official patch. Check the forum, or see the readme for whatever unofficial patch you plan to use.

And remember, if you have the GOTY edition you don't need any official patches, since it's already patched.

Official patches always need to be installed, for all of Bethesda's games. The unofficial patch for whichever game usually assumes that you have the latest official patch installed.

Morrowind is currently the odd one out by having two unofficial patches: The Morrowind Patch Project, which is an esp that corrects all sorts of ingame issues like quest bugs or floating objects, etc. The other one is the MW Code Patch, which alters the code of the Morrowind.exe to fix some bugs in the coding that can't be fixed with a mod. As they both do completely different things they are compatible and it is recommended to use both. Along with the official patch, of course.