If you can get a prescription, then I really like fluticasone for "today my allergies are killing me." It's a steroid nasal spray and I use it about twice a month -- using it for 2-3 days when things get bad then stop when they get back under control.

I do take claritin every single day, because I am allergic to grass and trees and pollen and air. The nasal spray is for things like "oh crap, today they're cutting the lawn at our apartment complex." I'm also allergic to perfumes and hair sprays and the like, by which I mean I am essentially allergic to air.

I wouldn't say that it provides instant relief, but it is a good short term nearly instant relief (like, it works within a couple hours).