For instance, you tell them to go to bed, they get up as soon as you go to do something else. You`re sneaking, you tell them to wait while sneaking, they stand up! when you want them to wait and NOT ATTACK because you have a great plan to drag the enemy onto traps or something, they barge forward blowing the trap or bringing the entire horde of enemies down on you. It`s also annoying that when something special or amazing happens, they never ask, `What was that?` or `What happened to you, you just vanished?`
Now what Modders have done in Morrowind, Oblivion and FO3 and done less glitchy than Bethesda can in Skyrim:
1. Created Followers that go into stealth with you and stay in stealth when told to wait.
2. Followers who can be ordered to stay back and not engage unless the enemy is really close.
3. Followers with many more voice talk than just `I haven`t seen that before`.
4. Followers that have several options for death to suit the Player. He can have a damage-sponge or someone who dies like the Player with even bring back from critical dying mode.
5. Followers with several dress modes that they can save. Have one for sleeping, one for the dinner time at home and several for fighting.
6. Hat on when fighting, off when no fighting.
7. Open locks, disable traps, even fix stuff IF they have the required skills.
8. They get annoyed if you take too much stuff off them without giving them anything back.
9. Ability to `pull` you out of a stuck position.
10. And finally, even join you properly in mini quests like they actually see what`s happening.
Now if Modders can do stuff like this, why can`t Bethesda Devs do and incorporate just one third of this for the THIRD incarnation of the Elder Scrolls?