Your favorite apps for Mac? + My WOW Moment....

So yesterday I decided that I wanted to get a new laptop. Was really set upon getting a Sony Vaio Pro because I have a good history with Sony Corporate, and they have sweet discounts (such as a free ram upgrade + 10% off). I have played with the Pro enough to know its Pros and Cons - mostly being how lightweight it is, and how Windows 8 is still a bit unprepared for high res.

By random chance on my way to the Sony store I stopped at the Apple store.

My last Mac was a 2011 iMac. I loved the heck out of it, but had to get rid of it (gifted to a needy family friend) because the display started to get burn out. After that I went with a Sony Vaio L Series - 1) because I felt Mountain Lion was detrimental to Mac. It slowed down my iMac significantly, 2) while adding little features (other than iMessages!). I did not really get a chance to play with Mavericks until yesterday.

And. WOW. Huge improvement! Seriously night and day difference between that experience and the experience my iMac had with Mountain Lion.

Then the double-whammy - THAT RETINA DISPLAY. Honestly, maybe the BEST display of any Laptop on the market right now. Its not even fair.

Walked out with the 13' Retina MBP. 8 Gb ram, 256 HD.

But I have been out of the Mac experience for quite some time now.....

So what are you favorite Mac apps? What do they do? How do they improve your experience using OSX?

P.S I know there may be some previous threads about this but I went back a few pages in the Forum and didn't find much. Just the one from the Verge on Christmas. Thanks in advance!

I would like to clarify, I am not trying to assert that the RMBP has the BEST display. I merely meant that it HAS one of the BEST displays.

Also, I have a wonderful Windows desktop at home. I personally choose to buy the RMBP, and am fully aware of its price premium.

PLEASE lets keep the posts about the APPS and not the " YOU SHOULD HAVE BOUGHT THIS!". Because I got exactly what I wanted.