As others have said, figure out what you like and do that.
For me, I have been reducing crystal malt to the point where I use very little now. I have made a few beers that have that famed "cloying sweetness" and when I look at the recipe to see what went wrong, sure enough, there's the crystal malt. Not saying that is conclusive evidence but that is my experience.
For pale ales you can do very nicely adding in a bit of wheat or oats for body, and I'll generally use Maris Otter instead of 2-row which negates the need to go silly with specialty malts.
In New Zealand we have something called Supernova malt from Gladfields which is some proprietary kind of light roast malt specially designed for pales and ambers where you don't want that heavy sweetness from the crystal. I'm a big fan of this malt and love the color it brings too.
I also stopped using Carapils after failing to notice any difference at all. YMMV.