ftp, I don't use heavily, so command line usually does it. for me Cyberduck is worth a look in the free category. Though Transmit looks to be the way to go for a great app if you use FTP a lot.

Word and Excel, I use iWork from Apple. Again my use here isn't heavy, if you need absolute 100% compatibility, Office 2011. If you are just opening, I think the OS handles both to some extent.

Beyond that, my general list is:

Adium (IM application)
http://adiumx.com

Unarchiver (Unzips rar, 7z and other less commonly found archives, and stuffit. Works like the built in OS X unzipper):
http://wakaba.c3.cx/s/apps/unarchiver.html

Perian (Quicktime codec to play most videos):
http://perian.org/

Flip4Mac, (plays WMVs in Quicktime)
http://www.microsoft.com/windows/windowsmedia/player/wmcomponents.mspx

Burn (Handy disc burning app for when disk utility/finder don't do what you need):
http://burn-osx.sourceforge.net/

Handbrake: (DVD to MP4 video ripper, and general transcoding app)
http://handbrake.m0k.org/