I am new to this hobbie and just need some help picking the best lipo battery for my DIY buggy. I got a 550 21T brushed motor with a 60amp esc.
I still haven't pick the servo and receiver yet, wanted to create my build around the motor and esc if possible. Any tips are welcome.

I've been out for a long while, and am getting back into it now. But have been doing FPV quads and wings pretty hard. 1/10th scale I assume since you are building it around a 550 motor. "Best" lipo is likely going to kick off some form of Ford vs Chevy vs Dodge debate. In 1/10 buggy's and stadium trucks, I like 2 cell lipo hardcase batteries. The Zee brand 2C 5200 mAh packs look to be about $35 for a two pack on amazon. And I use these pretty hard. They are only 50C batteries. But I seriously doubt a brushed setup with a 60 amp ESC would strain them. Serious racers usually are running Protek, Orion (are they still around?), Maclan, or some of the other very expensive LiPo brands. Best???? I'm still a Max Amps fanboy, and will likely always be. Though I can't justify super high end packs for the basher I am going to try to jump someone's house with.

Gens Ace is good, as well, I'm sure I'm missing a bunch. Should mention CNHL lipos get run in my FPV quads and slammed into stationary objects at mach Jesus, So I'd happily run those in a traxxas that I'm launching from a skatepark.

Hope that helps.

SMC Racing offers pretty much the best bang for the buck in batteries. They are well proven in the most demanding applications (EDF's) and their car batteries are equally good. They offer 2S Hardcase packs in a few varieties to match any need.