I've bred all 3 of these species quite a bit.
Crested geckos are the easiest. No heat and no light required in most normal homes. Can be fed commercial crested gecko food so no bugs are necessary either (although they do enjoy them as a treat if you want to do that). require a little more room than leopard geckos (20 or 29 gallon high aquarium is OK- they like to climb and jump). But the easy requirements more than make up for the room. This is probably a little better for handling than a leopard gecko, although both are OK.
Leopard geckos are also easy. They do best with some sort of heat source (like a heat pad or ceramic heater or night heat light). They are insect eaters, and require supplements like chameleons. They can be kept in a 10 gallon tank if you want (but larger is always better). They require a humid hiding place of some sort.
Bearded dragons are the most involved- they require the whole 9 yards- large enclosure, omnivorous diet (although adults do very well on rep-cal pellets with greens and insects for treats), full spectrum lighting and heat lights. They eat far more than the other 2 species resulting in far more waste to pick up. BUT- they are far more interactive and sociable with people. This is the beast to choose if you want a true pet lizard that will sit on your lap while you watch TV and look you in the eye and crawl over and lick your hand to say hello and can be put out on the floor to hang out with you and not just a terrarium animal that you can handle now and then like the other 2 you are interested in.
All 3 species lay eggs and females of all 3 will lay infertile eggs (females of most animals tend to do that when they cycle)- but the bearded dragons are far more likely to do this perhaps than the geckos.
The solution to that is simple- only purchase a male. If you are looking for a female- that can be a little tricky because sometimes males don't show sexual characteristics until later than at other times. But if you are looking for a male, usually one or more can be identified out of any group of lizards.