I'd say it really depends on your own needs. Ideally you'll have both, but budget may not allow that. You're better off buying one good pair than two cheap pairs.
Over pants will be your best bet for casual cruising, and being able to dress for your destination, like if you are commuting to work. They'll also have more comforts like removeable liners, vents & pockets making them more versatile.
Riding pants will offer less versatility, but will be more suited to actually riding. They'll fit snugger and generally offer better protection, like if you want to get a knee down & carve canyons.
Either way, you're going to be immensely better off than youll be with jeans. Ensure you're getting something with armour, or at least pockets for placing armour into. Also look for pants that have the ability to zip to a jacket so you can create a one-piece. If you're needeng pants that are water-proof, make sure they are also breathable.
Some brands that I have good experience with, and would recommend, include Alpine Stars, Motorrad, Joe Rocket & Belstaff.
Look for online sales but try them on before buying. Good luck!