I've used a third party charger, but not extensively. I've bought other parts and the Apple OEM items have a better build quality and will last longer, but the generics will get you by.
Never buy a third party battery though.
I have actually had pretty good luck with aftermarket batteries in the old plastic MacBooks. I have had one in my older black MacBook for 3 years and it has been fine. The Apple one blew up like a balloon at 4 years old. Machine is otherwise still kicking even though it is 7 years old.
You might check out Other World Computing (www.macsales.com). They often have deals on used chargers.
-KeithP