What flavor Ice Cream do you like? There is a carpet for everyone!
Personally, I am partial to Jungles although I am very smitten with our Jags as well.
All of the various types have pros and cons, and also each individual animal will have its own tendencies, etc...Here are a few major points...
*Jungles and IJ/WPs can be reluctant to eat rats, some do eat rats. But some do definately seem adverse to eating rats, despite tricks.
*Coastals probably have the potential to reach sizes that are more challenging than Jungles or IJ/WPs. Tigers (a coastal morph) are reported to remain smaller than typical coastals. Our Tri-stripes (another coastal morph) have not grown as large as I would have anticipated either, but maybe they will just keep growing, time will tell.
*Jungles are probably the most nervous of the major types. Not to say they can't become absolutely puppy dog tame. But of the types, they are in my experience the most nervous.
These are not hard and fast rules, and I can think of exceptions to these generalizations, but it should give you a place to start. I am sure others will jump on here with their opinions. There are subtle morphological variations as well. Some are difficult to quantify. To my eye, Coastal heads are longer and less "sharp" than a Jungle head. Older Jayas can develop wide, dragon like heads.
Oh who am I kidding?!? Get a Jungle. 
Good luck!!!
-----
Ben Team
Mark Davis
New Paradigm Herpetoculture
Captive Bred Morelia
404-247-3544
