The bag I've used for years, including two trips to Indonesia and a bunch of cross country trips, is my Porter case:
The great thing about this bag is that it turns into a luggage cart. I've hauled lots of heavy equipment used for diving and underwater photography using this bag at the airport. When I pick up my bag(s) at the carousel, I stack my bag(s) on the cart and I'm good to go. No looking around for a cart to haul my luggage since my luggage IS the cart! The Porter Case fits into the overhead and is easy to roll around when you're not using it as a cart. It's somewhat expensive but worth every penny. I bought mine used so did not pay full retail.
For a checked bag, I bought a duffle bag at REI and have been very pleased with it. I usually put the duffle bag on my Porter Case when wheeling it around the airport.