I purchase from both.
From the LHBS I purchase all my grain/yeast and 1 oz hop portions that I need for a batch and don't want to buy in bulk online. I also buy small items such as ball lock disconnects, irish moss, auto siphon, etc.
Online I purchase the more expensive items, such as hops in bulk and large/expensive items such as Perlick faucets/grain mill.
I support my LHBS as much as I can. They're nice people and I want them to stay in business. Their hop prices force me to buy those online though.