Milk chocolate is my favourite overall depending on brand and plain/dark chocolate to me is very plasticky and bland generally. Don't have many options for white chocolate where I am but what I've tried is ok and better than plain/dark but not as nice as milk. Not of fan of the European mainland dark chocolates like Lindt, seem much inferior to the american brand milk chocolates. However saying that if I'm treating myself it would much more likely be something toffee based rather than chocolate. Some of the supermarkets in the UK do a cheap 100g slab of milk chocolate for as low s 30p and prefer that to many of the expensive plain/dark brands with the ridiculous over the top packaging that are sometimes up to 10x as much. It's even competitive with other milk chocolate.
https://www.goodhousekeeping.co.uk/institute/food-reviews/milk-chocolate
Sometimes paying a lot less can actually get you a far nicer product.
