Meprolight and Trijicon both make good standard 3-dot tritium night sights. The TRUDOT night sights that come from the factory on Glock pistols are made my Meprolight (I'm pretty sure).
Heinie Straight Eights are also very good, with the rear sight tritium dot at the bottom of the bucket.
TruGlo makes a tritium/fiber optic sight, where the tritium capsule is placed in front of a strand of fiber optic so you get the bright fiber optic effect in both daylight and dark.
I personally want to try out the XS Big Dot with tritium inserts. The XS system does away with the traditional post/bucket sight picture for a shallow groove rear sight and large dot front sight.