pretty much just regular web browsing, video watching, a few lightroom/photoshop edits and school stuff lol
I like Dropbox to keep my files synced. With referrals, I have 30GB of FREE dropbox storage (I also know someone from Dropbox so I get free storage). I don't pay a dime.
Flux is nice if you want to keep working on in the night. It takes a bit of time getting used to it, but endure and in the night, turn it off and see how much difference Flux really makes! It's amazing.
If you like rss, ReadKit is pretty nice but Reeder is going to get an update soon to support Feedly so I'm looking forward to that.
I like Airmail, because it's simple and gets the job done. It also supports gmail keyboard shortcuts which is awesome!
Droplr/CloudApp. They are menu bar apps. You can drag screenshots/files to the menu bar icon and it automatically uploads that file and copies the link in your clipboard. I prefer Droplr because it has Notification Center support.
Caffeine is nice if you want your Mac to not go to sleep for a specified amount of time.
The Unarchiver from the Mac App Store unzips, untars, unrars, unstuffits, well basically it can extract most archive files.
Apple's iWork Suites. They're free, and for my needs, they are much better than Microsoft Office. And iWork for iCloud is just like Google Drive except it's faster and doesn't suck. You can even collaborate with people on files you upload, even if they don't have iCloud. It's similar to Google Drive, but again, much faster.
Alfred is a must have app. You can use it as a launcher but I recommend paying for the Powerpack. Then look at the stuff it can do with Workflows (you can get them here:
Alfred Workflows):
Protip: Don't download any anti-virus/clean my mac/free memory/fix disk type apps. You don't need them. Practice safe computing, don't download any unsafe files and you will be fine. There are no viruses that exist in the wild so an anti-virus program will just slow your mac down without doing anything useful. Clean my mac is useless, and the mac can take care of itself without you doing anything.