Lake Murray is beautiful, stayed at the Bed and Berth http://www.oklahomabedandberth.com/many times.="sdmahoney"]If you want to go up to Oklahoma, I think Lake Murray State Park off of 35 is a pretty decent place to go camping.
However to keep your money in TEXAS my vote is for Purtis Creek state park, just outside Eustace. The lake was actually built in the '80's as a fishing tournament lake. It's our favorite park next to our own personal park. Check it out.
http://www.tpwd.state.tx.us/state-parks/purtis-creek" onclick="window.open(this.href);return false;