I've been using this plugin for about a year now, and it has worked perfectly, and does exactly what I need it to. There are other instagram plugins out there, but this is the only one that gets down to business and does what I expect. Shows the latest n of my instagram feed. It has other features, but that's all I (or anyone, I imagine) need.
It had a small bug where images were grainy, and I submitted a bug report on the issue and I received a response very quickly. The plugin has since been updated and works perfectly. Recommended.