I used these:
Peltor 97010 Ultimate-10
Last I went to the range they worked just fine, however, I will probably be coupling them with plugs as well when I decide to go to the range more often than once every few months.
They are a bit "sizey" though to say the least, but I'm not shooting anything with a stock so it doesn't bother me. In the future I will probably be investing in some nice electronic headphones. Until then the Peltor's will do nicely.