Most obvious is the the blog running here which manages to catch most if not all releases:

http://indiegames.com/index.html

This site does a pretty good job at tracking all the bundles (a few on here you might not have known of)

http://www.indiegamebundles.com/

Not quite sure what this site is about but it's pretty good for noting titles that can be found at developer's sites only:

http://www.showmethegames.com/index.php

Tiggit also focuses on titles only found at developer's sites but also provides a free client that can install the free games and demos that it finds.

http://tiggit.net/

Actually in my opinion most of the best indie games aren't the "big" one's you see everywhere, but the one's that you have to go out of your way to find, usually hidden behind bland web-design. I got linked to some amazing "old style" indie RPG's and roguelikes from the codex, ALL of which I'd highly recommend.

While I tend to agree with you, the "original" indie bundle - the HIB - always trumps any other bundle out there. But yes, the obscure bundles do present great games that you might otherwise have ignored.

Tiggit is quite nice, I recommend it except it do not yet give you much control over where it installs the games. However, you can use it to search for games (it has a database close to 400 indie games and a few demos now) and go to developers site via links instead of installing through the client.

edit - oh yeah, and it only show free games, it do not show any other games.

I also use this www.indiegamemag.com