I use Chrome on my MBA instead of safari because my computer at work is a PC and i like that i only have to maintain one set of bookmarks. Otherwise i would totally use safari or maybe firefox.
iStat Menu or Magic Menu to monitor cpu and ram etc. Magic Menu is free.
Permute for the occasional video or sound conversion.
Dupe Guru, Clean my Mac, or Daisy Disk to find and delete duplicates or see where your disk space is going.
Ecoute for lightweight iTunes playback.
Ripit for ripping disks.
Reeder for RSS Feeds
Air radar for finding wifi points and their strength
TexWrangler (free) for text editing.
Chrome (with Ad Block Plus)
VLC
Evernote
Drop Box
Social Pro
Yasu
Chax (for iChat)
I used to use have Adium but I think it's better to save some MB by just using iChat with Chax (if you have Snow Leopard) to have a unified Buddy List.
Some of you say that Chrome is unnecessary. That may be true but Chrome has awesome extensions that make web surfing a better experience. Ad Block Plus makes browsing like the late 90's without all the stupid popup video ads, and annoying advertisements all over the damn screen.
Google has no idea what a decent UI looks like and that extends to Chrome. I also use merge tabs and reader on Safari alot. Ireeder is a chrome extension that does the same thing but sucks.
I agree with you for the most part, for some reason, Firefox slows down after a while. But why Chrome doesn't let you open Google on a new tab, you have the install an extension or whatever, come on!!!!
I don't understand why Chrome is a "must have" app. I think Safari for Mac is the best we have. If I were on windows I would use chrome hands down, but on a Mac? Doubtful.