I enjoy having first edition base, shadowless, and unlimited base all in the same binder to see the subtle differences in text/colors. Here is an interesting observation I made between these two Raticate. I’m sure these have been discussed but it’s fun for me nonetheless. 
Note the question marks and centering of the energies down towards the bottom.
Besides being far more valuable, I like the first edition base set over unlimited, purely for the sake of its looks. It’s colors seem more vivid, cuts more clean, and little subtleties like the picture that show how WOTC was figuring it out and making changes along the way.