You can use a simple car light bulb of 21W (voltage max = 12 volts) or a combination of several ones.
They are robust, very cheap and do not need a heat sink.
++ on car light bulbs
I do have an adjustable load ~1.5A max. For larger loads, the car bulbs are my "go to" solutions.
You can have some control of total load by how many bulbs you parallel (and/or serial). My favorite is the dual-filament (brake and parking light). With the dual-filament, you have 2 bulbs in one giving you more mix.
By the way, two additional notes:
(1) While they don't need heat sink, they do get very hot. So do be careful to avoid getting burn.
(2) Their current draw changes quite a bit - between cold start up and after they get full brightness. You can exploit this property, or just make sure you don't let that change mess you up.