[Zensation]

Almost every bromination I have seen whether using elemental bromide or N-Bromosuccinimide take place in glacial acetic acid.

Is there a reason for this? Solubility reasons? Why not some other acids?

[clarkstill]

I guess it's polar and protic so good at stabilizing the bromonium ion, but not a good enough nucleophile to compete with Br-.  Aqueous acids are out, as water would attack the bromonium ion.  I'm sure it would also work fine in neat stronger acids (TFA, TfOH etc.) but AcOH is a little milder.