Using Jekyll (w/ a good theme) + GitHub Pages is more than sufficient. More importantly, it's free, fast, and can handle large amounts of traffic, such as the front page of Hacker News.
A year ago, I used Wordpress on shared hosting, then my service was terminated once I hit the front page of HN (~300 concurrent users). I've been using Jekyll + GitHub Pages since, and I've had no issues whatsoever, aside from the occasional GitHub outages.
A variation of this is to push your Jekyll site to S3 and put CloudFront in front of it. It'll cost you a small amount of money each month (my sorely neglected blog costs me about $0.02/month).
Cant +1 this enough. Jekyll is damn easy to get started with and host on github. To start off, you can simply clone any of the existing blogs[0] or create a new one and get started. I also have a few rake and grunt tasks written to help you manage asset packaging (all of this totally optional, btw).
What makes Jekyll (and other static blogging engines) so great is that they give you far more flexibility than CMSes in certain areas. Just the other day, to see if I could do it, I wrote a Jekyll plugin to parse LilyPond music notation inside a custom Liquid tag[1]. After a day or two of research and fiddling — including learning basic Ruby — I can now have beautiful sheet music in my blog posts without any actual binary dependencies server-side. (In other words, the generated site is unencumbered by my build pipeline, and I don't have to worry about maintaining LilyPond/Inkscape on my server.) If I want to change the output in the future — PNG, SVG, even HTML/CSS — I don't have to touch my original Markdown content at all; it's just another render pass. And the best part is, Github will host the HTML files for free, regardless of whether Jekyll is actually running server-side or not. All your site updates are just a git push away.
The idea that your Markdown articles are definitive, that you can add custom grammar, and that your blog is strictly a view into your writing rather than a separate content platform, should be very appealing to programmers!
Jekyll with GitHub Pages is a great solution, but it's worth mentioning that other static site generators serve the same purpose and may be a better fit for you, depending on your preferences. Hyde is a very flexible static site generator based on Django, and Metalsmith is a very promising static site generator built on Node. Whatever static site generator you use, hosting on S3 is easy and cheap, and it's easy to automate deployments via Grunt or Gulp.
Were you using caching at all? There's a decent plugin called wp super cache that builds flat html files of all your posts and serves those instead of hitting PHP.
A year ago, I used Wordpress on shared hosting, then my service was terminated once I hit the front page of HN (~300 concurrent users). I've been using Jekyll + GitHub Pages since, and I've had no issues whatsoever, aside from the occasional GitHub outages.