Talking about convenient store coffee, I only drink black coffee americano so my review is black coffee only. IKEA has the worst coffee, the coffee beans is so bland and bitter like chinese medicine. McD is balance taste, better than Starbucks. Starbucks their americano alone is quite weak, too diluted I do not recommend, I think starbucks is more popular of their frappuccino drink, need ingredients like milk and sugar to cover their not so good coffee. Family Mart I like the most because of the light body profile.

McD breakfast brew coffee I drink quite frequent, it is average got nice coffee fragrance, passed my coffee test. Artisan cafe coffee it depends, some balance, some very acidic sour, I have tried one americano coffee from a hispster cafe that tasted super acidic, I describe it as not the comfortable acidic that normal people can accept. I guess the coffee beans have problem when roasting. Nescafe I didn't drink, but it should tasted alright.

If you can drink coffee without milk and sugar, just plain coffee, you can easily differentiate good coffee or bad coffee.

I recommend you a coffee chain that I recently tried which I think it is quite good, better than Mcd and Starbucks, it is Costa coffee at Shell station. I like Costa coffee, their Americano coffee, as usual I am an oldfag who don't add sugar or whatever in coffee.