Uhh - tough choise.
Alma - the most classic bag of all (IMO)
Speedy - always useful
Jasmin - new classic
Pros for Alma and Jasmin - they have much larger opening due to the long zipper.
But thats all I can think of.
Personally I would probably choose the Speedy - I find the others to be a little too "fine" although I think that the Alma is the most beautiful bag ever made by LV...
Good luck on your choise.