DOOM mod recommendations wanted.

I am currently in search of some new DOOM mods to play, but I am having a bit of trouble deciding which ones I should download. Would anyone happen to know of any particularly good DOOM mods? It would be most appreciated if you would be able to recommend some. :)

There's quite a few worth recommending, and if you have anything specific you're looking for it'd help to narrow it down.

In any case, 10 Years of Doom has a Top 10 list for each individual year from 1994 to 2003, and the annual Cacowards have covered each year since then.

Those would be a good place to start. Skim through 'em and see what catches your interest.