I am partial to the 4C for smoothing. All my Stanleys are corrugated. It just happened that way, but I do like the corrugated planes. I love a 7C and I have a 6C that I also love for short flattening jobs like a panel. For my wood surfboards, kayaks, and other curved things I like a No. 2, but that one is a LN. I still drool over a big heavy No. 8, but have yet to get one of my own.
All that said, my Veritas bevel up jointer, jack, and smoother are my go-to planes.