The usual PVC cements are fine. Anything safe for drinking are good for aquariums as well. Just lightly sandpaper, use a PVC cleaner, cement, and hold for 20 seconds. They say to leave it dry for 24 hours, but for the pressures we use, a few hours is good.
The big ones to avoid are anything metal (copper) or marked as mildew resistant.
If you read the packages, you should also avoid anything that says not to be used under water, but this is because of mechanical failure.