I have used liquid for years and find its ok - I tend to go for whatevers on offer at Asda, my local supermarket.
Asda's own brand - bio and colour seem fine and are alot cheaper than the others and I can't say I've noticed any difference with the cleaning. Using Persil at the moment, because it was on offer, but can't say I've noticed any difference in results. Compared to the cheaper Asda ones.
Tried 2 in 1 (as the advert says - save money) but prefer to use fabric conditioner, can't say I was impressed with the softness from a 2 in 1.