I don't know if many people agree with this, but I would also recommend you to give Apple's built-in OSX apps a try before installing replacements. I've used Ma

I don't know if many people agree with this, but I would also recommend you to give Apple's built-in OSX apps a try before installing replacements. I've used Mail, Calendar, Address Book and Terminal for many years without feeling a compelling need for alternatives. They usually work well if you're happy with the way they've been designed and don't try to bend them too much to your old habits. Other apps that I always install on new Macs are Homebrew, VLC, Adium, MacIrssi and then the usual stuff that's on any PC (Spotify, Skype, Dropbox, Minecraft, F.lux). And yeah it's important to install Xcode, otherwise your system doesn't have a C compiler so you can't do much. I think Git is also included with it.