Hey, I breed both,and they both have very good quailitys, my thoughts are that Leopard Gecko's are a little easier to handle and don't require a enclosure that very high, but they eat insects, so you'll need a supply/costs of crickets, phoenix worms, waxies (once in a while). and with Cresties, i know people who only give theirs, CGD only, but I give mine CGD, but also crickets,phoenix worms daily, it's not uncommon for mine to grab 4/5 crickets a day plus finish off most of the CGD and once, no more than twice a week a small cup of baby jar fruit,such as applesauce, pears etc; as a treat and a bit of a change for them,two of my little girls hatched Sept.13th '09 and their over 7 inches in length, they are excellent climbers, so they'll need some height to there enclosure,and as far as handling, they have excellent little springs in there feet for jumping, so you'll need to be careful when handling.
1.4. Frilled Dragons, 22.214.171.124 Bearded Dragons, 126.96.36.199 Crested Geckos, 188.8.131.52 Halmahera Giant Geckos (marginata), 1.1. Gargoyle Geckos, 184.108.40.206 Leopard Geckos, 220.127.116.11 Chinese Cave Geckos, 18.104.22.168 Fat-Tail Geckos, 1.1. Mossy LeafTail Gecko's, 0.1 Henkeli LeafTail Gecko, 0.3. African Banded Velvet Gecko's, 0.0.2 Madagascan Giant Day Gecko's, 1.0. Veiled Chameleons, .1.1. Cyrtodactylus irianjayaensis 1.1. Cyrtodactylus intermedius 1.4.Tibetan Frog-Eyed Gecko's