If you want to know what skills are considered bad by the community, you can have a summary of a survey rating all the skills
HERE. There are already over 174 answers.
If you take the survey, you will be able to see even more interesting data
Interesting.
There are a few that surprise me, though not many.
Corrupted Blade is actually a favorite of mine, even at 3 AP.
Vampiric Hunger would be broken in the original game, and sure it's situational if you run multiple armor restoration spells on multiple characters (which you honestly should), but there have been a few encounters where I was outmatched, and vampiric hunger saved my day. It does require a high amount of CON to take advantage of though.
I also kinda like Thick of the Fight. Again, depends pretty heavily on the encounter, but there are some where it's worth it.
Other than that, this list pretty much sums up my own experience as well.
You should make one for source skills, from skillbooks alone - I would be interested in that one for sure.
