If you simply love the Civic Sedan and want to fully load it, go for the EX. You can get a lot of nice equipment for under $20,000 - it competes very well with other cars in its class.
All of the features of the LX Sedan are found on the EX, of course; for example, air conditioning with air filtration, and 16-inch wheels, although on the EX those are alloy. The safety features (front air bags, side-curtain air bags, ABS, active head restraints) are the same, too.
In addition this trim boasts a 7-speaker (that includes a subwoofer), MP3-capable, 350-watt audio system that has handy steering wheel-mounted controls,  and also remote keyless entry.
The intermittent wipers may not excite you much, but they will surely come in handy. You might like the exterior thermometer, but you can also just hit the one-touch button for the power moonroof and stick your hand out to see how cool it is out there.