I'm not sure if this qualifies as worst or best use.

A couple months ago I spent 218k miles at the UA mileage plus store to buy a 50" plasma TV. I've been accumulating miles much faster than I use them over the past couple years, and decided I wanted a new TV, but couldn't really justify spending > $1k for a nice one (and why get a new TV if you can't get a nice one? my silly brain suggested). So I ended up using 218k miles for a roughly $1600 purchase.

On one hand I got something I probably wouldn't have shelled out cash for on my own (and I absolutely love the new TV), but at the same time that's a pretty poor redemption rate. The majority of those miles were earned through biz travel, so at least it wasn't my "money."

(First post, btw, from a long-time lurker who's been away for a while.)