Jane Hart has compiled her Top 100 Tools for Learning 2010 list.
With Twitter coming out on top for the second year in a row, the list (well the top 10 or so) looks as if nothing much has changed. Some new tools have emerged, but they are all relatively low on the list so far. There's been a bit of a shuffle in the top 10 and Facebook, Prezi, and Drop Box have made quite big gains.
Jane has some good sub-lists such as the 2010 Best in Breed List which categorises tools according to what they actually do, so if you are looking for something for a particular task, then this will be useful.
You might also like to look at the 2011 list which has quite a few new additions. One of the useful features of this list is that each is linked to an explanatory page on the site. Yoy can contribute to the compilation of the 2011 list.
Try the slide share on the site: this describes each of the top 100.