1. Autodesk 3D Studio Max
Its like the collest 3D Application ever(citation needed). I've tried Maya, Lightwave, and a little bit of Cinema4D but no one can beat 3DS Max(citation needed). Well then since I chose my path as an Apple Fan, bye bye Max, welcome Maya. Let see what it can do.
2. Total War series
There are two kind of people: those who like/will like/should like Total War, and idiots. I mean, cmon, hundreds and thousands of guys under your command, killing each other, blood everywhere, who wont like it. There are 7 series of Total War(including expansion), I got 7 of them. The next one, Empire, is really promising. But I can only wish I can play it :(
Great application for emergency small image editing task such as cropping, cropping, and cropping. We Mac also have a few competitor for Paintbrush but honestly, nothing as convenient and efficient and fast as paintbrush. Ow yeah...
4. Garena Client Application
If you play Warcraft 3, and play it online, I really dont have to describe why we need Garena. If dont, well then... youre not my type of friend :p Here is the short info: it is one of the most famous gaming server for PC, and yes it has lots and lots of user. Battle.net might be cool but Garena is a third party server. It means they will develop it more and more by time even if Blizzard leave their attention to another game *cough wow cough*
5. Visual Studio
Well, maybe this one is a little bit too much to ask. But hey... dont stop imagining things ;) Ive been through a lot of development IDE and I must say (even compared to XCode) VS is the best editor I've ever used. Good code sensing, simple file management and nice layout. XCode is good too but its too premature to give a head to head comparison between them.
So there you go. My big 5. Im currently enjoying my life with OS X but God knows for how long. Good luck, Lord Jobso.