Best milspec single stage option - ALG Defense ACT Advanced Combat Trigger for AR-15/AR-10

This is by far the best milspec single stage trigger available. Why you spend the money: .155 hardened trigger pins included, unlike standard .154 pins which are often softer steel this makes the break more accurate and crisper. These are $18 from geiselle by themselves. They also include 2 sets of springs a heavy hammer and light hammer spring allowing for custom pull weights down to a pull of 3.5lbs or 6lbs. Other triggers cost $20 less but don't include the higher quality pins or springs and are nickle boron only not, teflon/boron which is preferred for long term trigger operation.