You will find that an unbranded T-shirt is a reliable go-to piece.
Solar Eclipse T-shirt S Unisex Advice Black 100% Cotton
This shirt has a standard crew neck that never goes out of style, honestly.
METALLICA Ride The Lightning T SHIRT S-M-L-XL-2XL Brand New Official
A nice feature is the reinforced shoulder seams, a sign of quality for men.
Next Level Unisex Premium Plain TShirt Super Soft Blank Fit T-Shirt 3600 BANANA
A crew neck like this one makes the shirt easy to style with any accessory.
Next Level Apparel Soft Wash Cotton Tee NL3600SW
A t-shirt is the sort of thing you buy in multiples once you find one.