I prefer
Stephen (pro. like STEE-ven or STEE-fen) over
Steven. It just looks nicer.
Steven is fine, but seems a bit incomplete and just not 'right', and reminds me of the number seven plus a 't'. I'm not big on the name
Stefan though or the STEF-an pronounciation of Stephen\Stephan.
(my rankings)
1.
Stephen 2.
Stephan 3.
Steven4.
Stefan