Glock. And don’t let anyone tell you differently. You can pick the size and caliber you want. There are various opinions on caliber for a home defense gun. Wall penetration is a consideration, for example.

Glocks go bang. Period. You can treat a Glock like total shit and it will fire when you pull the trigger.

Sig Sauer makes great guns. H&K makes great guns on the more expensive side, but for pure reliability, Glock is second to none in my opinion.