Jenkins here too. Simple to setup and use and it has a tremendous amount of plugins to solve your problems (which is either good and bad, watchout for plugin inferno).

I'd probably try CodeShip or Drone.io for container oriented applications.

At work we use Jenkins on our own server for testing and creating project packages that we use in our custom deploy tool. Working with Jenkins is great, because it's open source, allowing you to tweak things you don't like.

For my open source projects I use Travis CI. Travis makes it ridiculously simple to setup jobs by using a config file called .travis.yml. The interface is really clean as well, making it my choice of CI.

I've been using Drone (http://readme.drone.io/setup/overview/) for almost 2 years. It's based on Docker so you can easily make build containers for any environment and attach other services, like database containers, so tests are a breeze.

Gitlab CI.

Installing GitLab CI is super easy on Windows, Linux, and Mac. Install CI on any other machine even with different OS and get go. You can even run such CI runners on your local machine and report it results to GitLab, awesome! I like build artifacts and pipelining. With build artifacts, you can upload a JRE for example, which is available for builds and deployment. No need to have such binaries lurking around your source files. CI supports virtually and any programming language or platform.

I use Jenkins, I love Jenkins, and I will use Jenkins. Yes, we have Go CD and other tools, but nothing beats Jenkins in terms of ease of use and setting up in such short span of time. And awesome community support is something you can't miss out!

Jenkins - it's really simple to use, open-source and very flexible since you can run your own bash scripts to do builds and deploys.

Gitlab continuous integration is a nice tool if you're using Gitlab, not using it myself though.