I like Sram chains with a powerlink, which enables you to take the chain off without a chain tool. Periodically, I take the chain off and put it in a plastic container filled with degreaser, which you can get in big bottles at any discount store. Let the chain soak for a while, then get in there with a toothbrush and scrub away all the grime. Keeping your chain clean is the key to reducing gear wear.