what’s the best vodka to get in the uk to mix

i’m going to get a bottle a vodka for the weekend and not sure what to get. i normally just get a bottle of smirnoff and mix it with coke or pepsi but i was thinking of getting some better vodka. i was going to get grey goose but after reading some people’s thoughts i’m not sure if i should get it anymore for the price of it. also for a young adult and got any price range up to £40-50