Well that's a pretty broad question - you could give us a little help with narrowing down your interests - such as weapons, scenery, creatures or quests
Here's a link to a list of most of the mods that were released on this forum last year http://www.gamesas.com/index.php?/topic/1150438-the-mods-of-2010/
They are sorted by category so should be useful for finding new mods - I personally added a lot of new scenery mods last year which completely changed the look and feel of my game - check out Vurt's listings and AOF's, there were also some updates to LGNPC - which is always a nice bonus