Cost: Inexpensive $10-$35 each
Great for bodyweight exercises, warmups, stretching, assisted pull-ups, travel, adding or lowering resistance on other exercises, and so much more. AKA superbands. Resistance bands can provide resistance in many exercises or assistance in exercises like pull ups. Resistance varies between bands and changes based on length, anchor point, and how you grip it. Bands are also an affordable alternative to cable machine exercises. Advanced lifters will find them useful accessories for many barbell exercises.
Good for warmup, rehab, and isolated muscle activation.
I prefer bands, but tubes can still be useful. See below for comparing the two.