Personally my go-to has always been the uesp, I prefer the layout, and its easy to get lost in its Lore section. I do however know that an increasing number of people are turning to the Elder Scrolls Wiki, because it uesp seems to be lacking in Skyrim content. I just think the Elder Scrolls Wiki is untrustworthy. I don't know why. And the Imperial Library is very comprenshive, and very good for lore, but I just never seem to use it.

Thoughts? What do you use? Do you use different ones depending on the TES game?

The Imperial Library is the best place for researching lore. Most of it is just the in-game texts in your browser, but there are some handy guides in there The Obscure texts are great, the archived forum posts are great. I never got into the forum there though.

For discussions on lore, I come here

UESP for game related info.

Never Elder Scrolls Wiki.

I agree, but for some reason, I think its purely down to loyalty, I use uesp for lore research.

Oh, I do too. I should have said that I meant for primary sources. UESP is usually okay for a quick summary, but for some of the more outlandish and metaphysical parts of lore, TIL is the way to go.

The one thing that UESP has that I wish the IL had is more links within articles. If you're reading an in-game text at UESP, you'll usually spot some links in the text itself that lead you to other articles and I really like that. I wish TIL did that, the search function at TIL isn't so great, . .