My hubby and I moved 11 times in the first 7 years of our marriage, so I feel like an 'expert' on relocation!
Liquor stores usually have sturdy boxes - they tend to be smaller (which I prefer) but the cardboard dividers in them come in really handy when packing glasses, knick-knacks, etc. Since we've been settled in one place for several years, I have been stocking up on those big stackable plastic containers with lids... I think Rubbermaid and Sterlite both make 'em. Anyway, those things are pretty sturdy and last forever! I just put a piece of packing tape on the lid (and both sides) and write the contents of the tub on the tape in big black permanent marker. When I have unpacked the tub, I pull off the tape and it's ready to be used again for something else. Works well for me!