Love the GearWall Panels, whether in the 8' or the 4' size.  Pretty much the foundation for the flexibility and modularity of all the accessories, hooks, shelves, baskets, etc. that make the Gladiator brand such a hit, at least in my opinion.

They go up easily, they're strong, they look nice and they just flat out do what they're supposed to do - they're also really easy to trim / cut to length and really convenient to work with and use.