Best laser for sighting in?

[stash]

Just curious as to what you use to sight in?...I like the lasers but a few complained about battery life and other issues.
Do you have a favorite laser to use? Cartridge type or the ones where it inserts in the end of the barrel?

thanks!

Stash

[EFBell]

I have the spud type. Battery life is good because you only use it for a few seconds every now and then. Has not failed to get me on paper yet. Usually within a couple inches at 100 yards.