Sam's of Gedney Way makes a great one.
Sam's of Gedney Way
50 Gedney Way, White Plains, NY 10605
The only burger I've had in White Plains is at City Limits across from the County Center, at the northern gateway to Central Ave. Pretty decent. Others seem to like Porter House (not sure if that's the meat they use also) and the Lazy Boy Saloon.
Best one I've had is at Porter House on Mamaroneck Avenue. Good quality beef and consistently cooked to desired temperature. Lazy Boy Saloon makes good burgers with different toppings, but I like my burgers medium and they occasionally overcook them. City Limits is pretty good as well.
Haven't tried burgers at places like Westchester Burger Co. on Westchester Avenue or Emma's - they've gotten decidedly mixed reviews on CH.
169 Mamaroneck Ave, White Plains, NY 10601