Favorite Internet Applications

Here's one more favorites topic. Hopefully someone else can fill in some of the blanks on this one. I'd be interested in finding more useful Internet related applications.

For an e-mail client, I've looked all over for an Open Source alternative to foxmail (compact freeware e-mail client). The only program that comes close so far is Sylpheed. I have tried Claws and the portable apps version of Thunderbird among others. Would be interested in hearing what others use and if anyone has any tips for working with Sylpheed.

For RSS, I'd like to find a nice client program to manage file downloading. So far, I just use the RSS features in Firefox.

For chat, I like Miranda and there's a portable apps version. Still looking for a good Linux chat program, maybe ayttm? I've tried gaim/pidgin and it's been buggy both on Windows and Linux for me.

For ftp, I definitely like Filezilla. Again, portable apps version is available for flash drives.

For web utitilies, I like httrack. I also like having a ftp download accelerator program. There are a couple I use that are freeware, but still looking for something better. Anyone have any suggestions?

Also, any suggestions for Usenet newsgroups? I know Sylpheed can handle them, but a dedicated newsgroup reader is nice too, so it doesn't get too cluttered with both e-mail and newsgroup posts to go through.

Probably the most widely used category is the web browser. I've been using the portable apps version of Firefox on Windows. Anyone have any recommendations of good plugins/add ons for Firefox? There seem to be so many. It's hard to find the best picks. For reading documentation or checking browser compatibility when creating a web site, I like lynx (doslynx available for Windows) or links. Any other recommendations in this area?

Are there any recommendations for Open Source firewalls? I've seen a few at Sourceforge, but haven't tried them out yet.

I'm sure there are other Internet applications I haven't covered. Anyone have any further recommendations?