The blue tit (Parus caeruleus) is currently (as at 2014) number 3 in RSPB Big Garden Birdwatch top 20.
Unlike it's cousin, the great tit, the blue tit seems happier away from its natural woodland habitat and is more eclectic in its taste; it is happy with seed, peanuts, fat balls and the like as well as keen on cleaning up the aphids from the roses in summer. If you have blue tits visit your garden you probably have them all year, not just in winter.
Blue tits are common, a bit dull, have no real song, they are just ordinary, but they have one thing on their side, they are really cute! Apart from the robin perhaps, I suspect the blue tit has done more to further the popularity of birds with us human beings than any other species. Their readiness to make a home in a nest box in almost any garden makes them particularly popular.
Quite often people can think they have a resident three or four birds in their garden in winter and yet, in reality, they have a constant stream of different birds popping in. Ringing in gardens has revealed some quite interesting facts about actual number as against perceived numbers.
They may be common but they really are lovely little characters and always entertaining on the garden feeders with their acrobatics.