Seeing a Firefox Extensions topic, and more recently, an Opera Extensions topic, I decided to create a Chromium-Based Browser Extensions/Apps topic (notice I didn't say Chrome). I said Chromium-Based, because that's what Chrome is, it's based off of Chromium (the open-source browser), and so are all the other browsers that look like Chrome, but with tweaks and whatnot, like SRWare Iron, Chrome Plus, etc.
Anyways, to start things off, here's what I have installed so far (I use Chromium by the way):
AdBlock: https://chrome.google.com/webstore/detail/gighmmpiobklfepjocnamgkkbiglidom
Auto Replay for YouTube: https://chrome.google.com/webstore/detail/kanbnempkjnhadplbfgdaagijdbdbjeb
Neat Bookmarks: https://chrome.google.com/webstore/detail/nnancliccjabjjmipbpjkfbijifaainp