OXO is my choice because the measuring area is angled & designed into the plastic.
Buckets for water changes & aquarium use don't need to be FOOD grade plastic, but should be labeled
once you bring it home so no one accidentally uses more toxic chemicals in them.
I use the OXO bucket exclusively for floor cleaning type duties. Personally it sits too low for water changes & the lip of the bucket is too wide.
For water changes, I use these......
But I need to switch to one of these instead since water pours without splashing.
Or this 4G square pail.
Plenty of options & colors available.