I know the placeatme command causes problems in Oblivion. My question is are there any others, and do they apply for Morrowind and Fallout 3 as well. The reason I ask is I used to own Oblivion and Fallout 3 for 360 but stopped playing because of bugs and glitches. Now I am thinking about getting them on steam, but I'm not sure. If someone could just tell me the console commands to stay away from, and as long as there aren't too many of the good ones I will make the right decision =) Thank you in advance.

I think I found a few other commands that act as minor annoyances, and can be fixed if used so they aren't game breaking commands like place at me. Also can the moveto command be used on corpses of NPCs that have vanished? and if not how do you get an NPC that has disappeared back to existing? Thanks Again.

the only one I am aware of that can occasionally screw up some quests is the command to reset quests or advance through specific quest stages. (SetStage BaseID StageNum)

I tried it once when I messed up a quest due to my own choices and it seemed to work without causing any major problems, but changing your quest stages can have very unpredictable results.

Also, if you are "really" cheating and decide to increase any of your attributes close to 255, if you advance a level or use a magic buff, once that attribute or skill passes 255 it will go back to 0.

Here is a great tutorial on console commands:

http://www.uesp.net/wiki/Oblivion:Console_Command_Tutorial

Thanks BootySweat

For missing npc you could try this, in the console:
1. type: save current1
2. go to your save game folder, open the text file named current
3. search for your missing npc and note the npc id (the one far to the left)

Back in your game:
1.1 type prid "npcID"
1.2 moveto player
or
2. "npcID".moveto player