I've always been very pleased with the service I've received from Internet-Ink'
Delivery is very speedy, and the prices are reasonable.
I bought a 'compatible' dell cartridge once, but the printer wouldn't accept it, so it was false economy. I have always stuck to the genuine article since, although it is more expensive.
My next printer definitely won't be a Dell, so I'll be able to use some of your cheaper cartridges.