This is the 3rd time I have rebuilt my website. It has gone thru a few iterations. This time around I started with deciding to rebuild my vps hosted with digital ocean. Before I had just used the ubuntu image with WordPress included. The problem that is that it runs with Apache instead of nginx. After running that setup for a year it kept crashing every few weeks both on the $5 droplet and the $10 droplet. To compound things I actually run WordPress Multi-site so I was really maxing out the limited memory available on the small droplets.
The solution was to switch to nginx. Running wordpress ontop of nginx you can squeeze a lot more performance from a small vps. It used to be fairly complitcted to setup with a lot of files to edit in order to get wordpress to work correctly but then I found an amazing tool called easyengine.io which makes the setup part competely painless.
so the current web stack here is namecheap for domains, cloudflare for dns, digital ocean for vps hosting, ubuntu 14 os, WordPress Multi-site, and wpmudev for a variety of themes and plugins. Which I am currently using to power 6 to 8 separate sites.