Zyrtec is what my doctor recomends... they all work well, but Zyrtec has the least side effects, and can even be taken by pregnant women (check with doctor first). It's a very safe drug. Claritin is known to cause headaches in about 10% of users... Zyrtec isn't.
Zyrtec is also more effective on Hives and skin conditions....
I use Zyrtec for my hives. It is very effective. Recently I tried out Allertec just because it was so much cheaper. It worked just as well for me.