I like just about any type of aged wulong, and I've tried many/most types that I know of
Hou De, zen8tea, Imperial Tea Court, and Red Blossom are good ones to start with.
zen8tea's don't taste very aged, but they do have some of the aged qualities. The first one I got had just the slightest hint of mustiness, but airing it out for a few hours transformed it pretty dramatically. These seem to be high-fire teas that were probably fairly heavily roasted over the years, so although I don't have much experience with aged high-fire teas, I suspect that this reduces some of the aged qualities.
Imperial Tea Court has one that's very inexpensive and good if brewed right. When I first got it, it seemed decent but not great. Then recently I brewed it in my aged wulong yixing pot, taking care to maximize the heat, and it came out intensely fruity and sweet - some might have even found it too sweet, but I really like it. At ~$11 for 4oz, I'll probably grab some more.
Red Blossom has an aged baozhong that is a good solid one. It's not very complex, but it is a very good basic one that will both make a good introduction and serve to satisfy any craving for an aged wulong when you want one more casually.
As far as being skeptical of aged wulong in general - I forgot to mention that there are also tea competitions for aged wulong. I was chatting about this with Melody (zen8tea) and she showed me a picture of a 3rd place one that was very expensive. So yes, there are some that just get forgotten about, but it is an official type of tea (so to speak). They're just not easy to find here - especially when you consider that tea newbies get it drilled in their heat that fresh is better. This would also be why Seven Cups sells their 1+ year old yancha at a discount. Even ones that were just forgotten about can still be good if they were kept away from humidity and then sealed tight. Most of the roasting is done just to drive off humidity.