I think you will find if you plant them in the garden, they will take very many years without flowering to become a decent size. I would throw them away.

Thanks for that. I'll do as you say and buy some new ones!

I would plant the big ones with the smaller ones around them. I hate throwing things away. the larger bulbs may well flower this spring and the little ones will take a few years to flower. every year I buy new ones too.

Potted bulbs are hit & miss. I'd buy new ones especially if you are talking about tulips. Discard the lot & buy new bulbs. They aren't very expensive and you can take advantage of all the new varieties & colors. Get some 'early season', some 'mid season', and some 'late season'. They decline quickly after the first. Things that cause this - development of seed pods, cutting the green foliage prematurely, depleted nutrition in the potting medium, lack of adequate moisture after the blooms fade, mold and pathogens, etc.

I discovered this year (for future reference) that some tulips are marketed as coming back every year. I have two varieties that do this and the rest aren't worth keeping.
Mostly the other varieties come back small and poor if they come back at all. Also for repeating ones you might try one of the the wild varieties - smaller flowers but spread rather than die...(eg Tulipa sylvestris)

Odd in a way. I planted 500 Queen of the Night in our last garden. When the Badger dug them up and ate them a few years later there were 3,500 or so of them, all flowering as good as the original. The 500 or so Attila which were planted at the same time in the same soil and in the same area, hardly did anything beyond flower every year afterwards.
Basically with the hybrid tulips you need to feed like mad to get them to return. And the feeding has to be done from the second the leaves appear above ground. They also need a really good baking in Summer once they are dormant as well. So, very rich growing conditions and hot Summer sun is what you need. If you cannot provide those conditions then yes go for new ones.
The rules are slightly different for the species ones where they will come back year upon year, if planted where they are happy.

Thanks everyone for all the advice. I usually get some reflowering so I'll plant the old ones in the garden and buy new for the pots. I'll remember to feed in the spring. Thanks again.