What I notice is the crew neck, which has a slight stretch for easy movement.
Riddler Criminal Batman T-Shirt Officially Licensed DC Comics Villain S-3XL Tee
The crew neck here is simple, but it gives the whole shirt a polished look.
Mexico World Cup Personalized Shirt – Custom Name & Number Fan Apparel
With a solid pattern, this T-shirt avoids the busyness of printed designs.
Lucky Green 3 RDRM Redrum Nation v2 Tshirt
What makes this one great is its solid pattern, letting the cut do the talking.
Oxidized Green 4 Redrum Nation V25 T-Shirt
A nice touch is the solid colorway, which stays true wash after wash.