You want to make sure you dont keep the original grip style. It was designed for people to use it with excetionally tiny hands at the expense of normal men. The worst choics for normal to large hands is probably the Tango Down. If you dont like the factory grip stay away from this grip its even worse in the ergonomics department. Too narrow up top and way too fat on the bottom. Maintains the cramped trigger finger problem and you cant comfortably place the web of your hand into the grip without causing your trigger finger to be bunched up and angled down.
Look for a grip with beavertail backstrap. It will allow you to place the web of your hand into the arch and have the trigger finger in the right location and spaced back if you have med to large hands. The arched back strap in the palm area is too fill larger hands better but its not needed of you are medium sized in the hands or use gloves. The three grips that I have used that have the propper beavertail for my hand size are the Ergo, the G27 and MIAD.
The Ergo is narrower than the factory grip. Females and small handed people usually like it if they have fingers long enough to manipulate the safety. Mine are med/large so it was too narrow. It has no storage and mild finger grooves.
G27 is wider than factory and feels pretty good. I dont like the prominent finger grooves and the grip storage is NOT waterproof and frankly kind of ghetto. Not a bad grip though.
MIAD is wider than factory but narrower by a smidge than the G27. I prefer it because of its superior grip stoage and modularity. The beavertail is the same as the G27 but the arched back strap has the arch centered in the back strap instead of peaking slightly lower where it should be. I use the beavertailed backstrap with no arch for this reason. I also like the fact it can have no finger grooves on the front strap.