Your choice depends on several factors. These include (but are not limited to) what you like, what is affordable, and what is available. Other questions include have you had experience with leopard geckos in the past, do you want to start small for the experience, and is this intended to be a hobby or a business?
If you're a filthy rich rock star, then get all of them. 
Assuming that you've had little experience with leos, intend this to be a hobby (at least initially), and want to get started on a shoestring budget, then start with normals or whatever else is cheap, available in your area, and healthy. Once you have a couple of years experience breeding them, then you can branch out. And a number of the morphs are produced by one or two mutant genes. Once you get an albino or some such mutant, you can breed them to your normals.
But the very first thing to do is to do your homework on the care and breeding of leopard geckos. Read the web sites and forums, check out the books, and join your local amateur herp society. Herp societies are excellent places to encounter more experienced people. You can learn from them and sometimes get healthy animals that are excess to their needs.
Good luck.
Paul Hollander