Which Europeans discovered America before Christopher Columbus?

Without a specific map or route which specifically
documents proof that "A" long trip was made coming our way, it would be hard to
determine exactly who visited us first.

Also, be careful
with the word "Europeans". References have been made about Norsemen and Celts, Vikings,
and other groups, even Egyptians! (....and, of course,
aliens)

Now, if you want to go on the safe side, it is
accepted that people from Siberia travelled through the Bering Strait (when it was
frozen and people could walk over it)  over 20,000 years ago all the way towards what we
now call Central America and, generations later, developed massive tribes called the
Olmecs, Mayans, Aztecs, and the Incas.

If you reduce your
argument to Europeans, you would be talking about continental Europe, and that is made
of Eastern and Western Europe. No specific information (except for the one I wrote
before) is historically accepted about actual continental Europe voyages to this side of
the ocean.

But that is the beauty of history: There is NO
"final answer."