What kind of standard switch do I need to replace this dimmer?
This is very easy: Just connect the black wires to the switch. 

Be sure, of course, to turn off power (and verify it's off using a non-contact tester). 

You can remove the two black wire nuts, and then just connect those wires directly to the screw terminals on the switch. 

New switches will also have a ground screw (green) that should be connected to ground (using bare copper). I can see some ground wires twisted in the back of the box -- it almost looks like there's an extra piece there that used to be connected to a switch, you can maybe use that. If not, get a 6" or so piece of #14 bare copper wire and twist it into the existing grounds, and then connect to the green screw on the new switch.