The Photon is a nice little light, but I carry a Petzl Zipka headlamp which I find very convenient (I don't always wear a brimmed hat) and which is just bright enough for night hiking if necessary. When there is a strong possibility of hiking at night I bring instead a Princeton Tech Eon, which also works great in camp.
REI carries Montrail shoes and boots. They're my favorite.
REI liner gloves hold up better than Seirus liners, and they also carry Manzella brand. I like the Manzella Windstoppers, but don't expect them to do more than stop wind. If you want something more, try the REI One mittens or gloves.
As previously mentioned, REI carries National Geographic Topo! (state) mapping software, which I highly recommend (make sure you get version 4, not 3, otherwise you'll have to buy an upgrade). They also have Garmin GPSs (which will eat that gift card up in one gulp).
REI carries some Hennessy Hammocks, which IMHO make a great sleep system. HH are heavier than ultralight (36 oz complete with tarp), but I'm stuck on mine 4-season. No bug problems, either.
You can get SmartWool, Thorlo, Bridgedale and other socks. Buy three get 10% off (most of the time), and they wear well. I'd stay away from REI-brand socks; they don't wear as well (this from an REI employee). I'm fond of the SmartWool Adrenaline Crew paired with Montrail Vitesse shoes.
Nalgene Cantenes are lightweight and have a convenient wide-mouth. REI also carries Platypus.
REI carries Sunday Afternoons hats. They're lightweight and cool with a wide brim, if a bit ugly.
Sea-to-Summit dry bags are good, but you can save weight with the Sea-to-Summit Ultra-sil Dry Sacks, which are waterproof unless immersed.
I like REI-brand CoolMax t-shirts.
I've spent thousands of dollars at REI in the last few years, but I don't recommend buying any of the main items there: backpack, tent, sleeping bag, sleeping pad, ground cloth, or trekking poles. What they have is just too heavy for most situations, and you can get lighter gear from many other small companies mentioned here on BPL.