I'm surprised how many people would change out IE as a top number one priority, I haven't got around to it yet this install, and to be honest, it's not bugging me.
I'd probably go NOD32, so nothing gets in to eat my hard drive...
Then Steam so I can download all my old games and buy new ones...
Then iTunes so I have a constant supply of podcasty things to amuse and entertain me.
I'm no MS fanboy, I just don't think IE is as bad as it used to be, especially as MS seem to steal most good ideas and put them into a later version of their own stuff