On Simba (Mac running OS X 10.7.x Lion):

– standard Mail client for mail.
– Camino for browsing. I’d probably choose Firefox, except that my wife uses it. We run different browsers so that we can keep our sessions, bookmarks, etc, separate

On Hobbes (Mac running OS 10.4.x Tiger):
– again, standard Mail for Mail.
– Firefox for my browser

At work
– Outlook for mail
– IE 8 for browser
I don’t have any control over this – company has 100K+ machines and enforces standard software to minimize support issues.

On my Palm Pre, I use the aptly named “Email” and “Web” apps.

I’ll pretty much use any email client or browser that’s put in from of me. Any of today’s option are far better than what I started with (some Unix-based client for mail and Mosaic 1 for web).