Stock 1500psi gauge that comes with the PMI Piranha Pro TS and EXT.
Marker Setup:
PMI Piranha Pro TS (G3), Equation MS Barrel, Shocktech Spring Kit, 9-volt Revolution, PMI Pure Energy 48ci HPA.
Strengths:
Accurate, easy to read, durable, small range of pressures available (0-600psi good for low pressure guns).
Weaknesses:
It will leak if you don't put some teflon tape on it when you screw it in (this is the case with any gauge, though).
Conclusion:
If you want to have something a little bit custom, and make it easier and more accurate to read your operating pressure, this will do it well. For $13, it's a nice little upgrade.