What's the best way to thank or gift an agent who worked really hard on our behalf, but with whom we ultimately did not purchase a home?

Background: We've been looking for a home since summer. In the fall we started working with a great agent. Started out by establishing that we had seen, and didn't like, anything currently in the MLS system. Discussed the type of home, neighborhood, and area we wanted to find. This agent then went actively searching for houses. Called people they knew in ideal neighborhoods, knocked on doors, sent feelers out to other agents. Found & suggested great neighborhoods we hadn't known about. Got a lot of "before coming to market leads" for us to consider. Real proactive go-getter.

While looking at town X, the agent suggested that we'd also like similar town Y, which was just over the state border. A state in which they weren't licensed. They referred us to a similar top-notch agent in that state, and it looks like we've found something.

What would be an appropriately valued gift or thank-you for our first agent, who hustled for us but ultimately didn't directly get the sale?