For proper decongestant, be sure you are getting pseudoephedrine as the active ingredient, not phenylephrine. Personally, I prefer pseudoephedrine with guaifenesin.

For brand names, that's Congestac or the CVS house brand. I cannot remember the full CVS product name and they don't list it on their website, but it is in the pharmacy behind the counter and I think it might be the only CVS branded item with pseudoephedrine (definitely the only one with guaifenesin in it), so it is easy to find on the shelf. There's also Mucinex D, but that's usually super expensive. In terms of price it is Mucinex > Congestac > CVS.

Edit: I agree with jamesjim1k on the manual action, but since I have allergies on and off, I carry decongestants with me anyway, so I tend to go ahead and take one before the flight. The manual action helps if I forget to do that though.

BillJ