I've a Freeplay Indigo wind-up lantern, and I like it pretty well. It is a well built lantern, and it performs fairly well (I've not done any extensive tests).
It has the option of using an A/C adapter to charge it's internal NI/MH batteries, and it last 2-3 hours like that on high. I can crank it for a minute, and it will last about 5 minutes on high, and around 30 minutes on low (be advised these are WAG's due to the fact I've not actually timed it).
It also has a single LED in the front that seems to last a bit longer than the actual lantern part with the multi LED cluster.
I bought mine on clearance at Target for around $17.
If anyone is interested, I can do some runtime tests on it. I don't have any sophisticated equipment, so it'd just be my eyes and a timer.