What kind of bird do you have and is it tame or not?
Personally, I do not clip my birds. However, so far every bird I've gotten has already been clipped when I got it (whether from breeder, rescue, or rehome). And I can see the value of a bird being clipped somewhat when first going to a new home - panic flights when they don't know the layout of the home and windows can be dangerous. Once they settle in and know their way around, I've found windows to not be too much of a concern.
There are some valid reasons to clip birds and some non valid reasons.
Flying away - Birds are sometimes clipped to keep them from flying away. If a bird is flying away because it's scared, you need to gain its trust. Clipping the bird does nothing and may, in fact, harm the bond of trust. Sometimes a bird is tame and the owner just wants to take it outside. In this case, clipping can give a false sense of security; even if a bird doesn't seem capable of flying indoors, if something really scares it outdoors (like spotting a hawk or something that makes it think of a hawk, like a plane), it can usually still fly away. It may not get as far away, but it more likely to end up in the top of a tree without knowing how to fly down, or to get killed by predators.
Aggression - Clipping will usually not do much to reduce aggression. Sometimes a person will have a bird that flies and attacks and will clip to prevent that; but it's like chaining up a dog that bites. It might make it harder for them to bite anyone, but doesn't help solve the underlying problem. Still, in situations like this, a temporary light clip to keep attacks under control while the bird is trained more can be ok.
Safety - Clipping for safety in the home can be a valid reason, depending on the situation. Some birds just never get the hang of avoiding windows - usually from being clipped before they ever learned to fly. Some birds may fly after the cat. Some birds are just too nervous and easily started into panic flights and a light clip to keep them from flying into things for a little while can help. Clipping is definitely not always safer in the home, though. There are also many situations where a bird is safer flighted.
Clipping is also temporary, when properly done. A bird that is clipped very severely may constantly damage new blood feathers as they grow in, and have difficulty becoming flighted, but in most cases, with a normal light clip (or baby clip), the bird will be able to fly again within a year - often less in the case of small, lighter bodied birds.
There are also some real dangers to clipping. Any type of wing clip will reduce the support for blood feathers growing in and make them more likely to be damaged and bleed. With a good wing clip that is not too short, this risk is fairly low but still present.
Wing clips that are too short can result in a bird that falls, rather than glides. Some heavy bodied birds can fall hard enough to injure themselves badly, splitting their keels or breaking bones. It's usually not an issue with birds that are fledged and then clipped lightly but still a risk. Sometimes the clipped ends of feathers can poke a bird's sides and irritate them until they start chewing on the feathers; it's thought this can sometimes lead to feather plucking. Clipped birds may be less able to avoid dangers, if they happen to flutter to the floor, and may be more at risk of being stepped on or attacked by other pets.
Along with these risks, there's also simply the reduced exercise available to clipped birds. Flying even short distances provides more exercise than a lot of walking and climbing around. As far as I know, there is no actual research on how flight affects health, but it seems pretty likely that flighted birds are going to be more fit and healthier than most clipped birds.
I guess it's up to every individual. I really don't like the idea of clipping a bird for life. A light clip done as a one time thing for a specific situation is different though.