I have four bearded dragons, and they are great pets! They are a bit more expensive to keep than leopard geckos. Beardies eat a lot as babies/juvies (one of mine has eaten over 100 crickets in a day), and they require UVB bulbs, which cost about $25 each and need to be replaced about every six months. They also require a larger enclosure than a leopard gecko - the minimum for an adult beardie is a 40 gallon breeder, while I think an adult leopard gecko can be housed in a 10 or 20 gallon tank. Beardies do get bigger than leopard geckos, and are supposed to be a bit better with handling, though I don't have a leo, so I can't really compare them. Adult beardies are a lot cheaper to feed than baby beardies, as they switch to mostly greens and only about 50 crickets a week, and they are also a bit calmer (and generally sturdier) as adults, so you may want to check into adopting an adult beardie if you decide to go that route.

I wouldn't recommend housing more than one beardie in the same tank (and I believe the same is recommended for leopard geckos), as they are solitary creatures and can be aggressive toward others. So if you want more than one, be prepared to have more than one enclosure.

In addition to bearded dragons and leopard geckos, I believe crested geckos are also considered a "starter" lizard. I can't really help a lot with advice about leopard geckos or crested geckos, but I do know that both leos and cresties are nocturnal (while beardies are diurnal), and they don't get as big as beardies. Out of the three, I would pick a beardie, though I am obviously biased

Hope that helps