my yahoo looks better than personalized google. google video is a nice novelty that I use.
gmail I like better, as I tend to agree w/ the labeling method of organizing (and I'm a pack rat). Yahoo's NEW mail interface looks extremely promising.... but again, I like gmail better. gmail also has more features w/o paying.. for now.. neither have a key feature of fastmail I want/need. It's what has kept me from switching completely to either one.
search... google wins.
IM: googletalk as a client sucks, but I like what google want's to do.. make IM a standard protocol.. Jabber FTW! Trillian is my almost perfect client... I loved adium on OS X...
In other words... they both better keep on chuggin, competition is good.