I've been playing everything from DR Strings, Everly Strings, GHS to Dunlop and I've been quite happy with all of them. But it's always been a balance between price, sound and quality.
I play in a BEAD tuning and having to always by 5 strings sets to get the right string gauge, or either by pricy 4 string sets, I was very pleased to find the Ernie Ball Beefy Slinky sets. Not only are they the cheapest of heavy four string sets I've come across, but they have a snap to them that really surprised me. Check 'em out! They sound great and keep the tone!