pastem8 is a simple pastebin website with a few cool features packed in.
once you make a paste, you are redirected to that paste's plaintext url. you can enable syntax highlighting (using hljs) by appending, for example, ".html" to the url.
if you don't like the default highlighting theme, you can again append, for example, ".zenburn" to the url. a full list of available themes is available at /meta, and the default is github-gist.