Who the hell uses The Tower in Oblivion? 5% Reflect Damage is incredibly weak and Open Average Lock? HAH, Useless! Oh it's only once per day? Even more useless! Just get 1 measly lockpick and you can pick open any lock from the start. (That would be in Oblivion) Or just level alteration.
Personally, I use the magicka boosting or the stat boosting ones. I never remember that I have the Greater Powers so they become useless for me, sadly. The Lord is a great sign for characters that aren't good with restoration and don't have a sizable magicka pool. It's really magicka efficient and is a Lesser Power. When you have so much health that is becomes useless then you have either gotten so powerful you don't need it or you have 100 alchemy and can make unlimited restore health potions.