Crimson Crate

The whole point is the heart reward you always get, and this pool is friendlier than the Corruption version. The Rotted Fork is a real early summoner weapon rather than a curiosity. The Crimson Rod parks a raining cloud over a boss and keeps chipping while you concentrate on not dying. The Panic Necklace is one of the better things you can wear into Skeletron. There is no genuine dud in the group.

Breaking hearts underground summons meteorites and forces a Brain of Cthulhu fight once you pass the third one. Fishing sidesteps all of it. Dig a small pool inside surface Crimson, drink a Crate Potion, and you can collect the entire reward pool in one sitting without ever going down into the biome.

Coins, ore, bars and bait fill out the remainder and are not worth planning around. The potions are the exception. Fish crates at any scale and Spelunker and Gravitation stacks pile up for free, which is worth more over a playthrough than the metal is.