250ml, 500ml, 1l, 2l and 4l are typical sales units for dairy products in the UK. And before you say "look, they're using powers of two, metric is all a sham", those particular sizes map quite closely to the old sizes, making it easier for uber-conservative (and ardently anti-European) Britons to accept and understand metric.
I'm not conservative or anti-European and I prefer to work in base 10, with consistent ratios, not having to remember the different number of ounces in a pound, vs the number of pounds in a stone, vs the number of fluid ounces in a pint. I like that I can think of a litre of water and have an immediate feel for what a kilogram weighs, or what 100mm looks like.
I'm 43 years old, so I went to school post-initial-metrication, but there are still plenty of hold-outs my age and older who "can't stand metric", including my otherwise-sane wife. But at least we're 30 years further along the metrication process and can report that the world won't end if you do get with the program(me).