Best:
Tommie Tippie nappy wrapper
Bumbo
Any bouncy chair (cheaper ones will do but the musical ones are nice)
Avent Steriliser
Lindam night and day feeding system
Baby walker - although I broke ours, oops.
Worst:
Avent bottle warmer - good when they're little but as they get older a microwave will do just as well to be honest (just shake to get rid of hot spots).
Door bouncer - They're cute, but we never used it.. whether thats because it's not our house or not, I don't know but it's just the kind of thing you put away and forget about. The little ones you can buy are a good idea though.
Baby bath and top and tail bowl - A top and tail bowl is a good idea, but you can easily buy a small bowl for a lot cheaper. Next baby, we are just going to buy a bath support to go in the big bath as they outgrow those little plastic baths so quickly!
I can't think of anything really BAD i've bought Bethanie, except 1 thing, a bath seat from Tesco. It wasn't cheap, but it was blue plastic and would scratch her legs when you tried to take her out of it.