I like my Arai GP-5W, no visor, clear lens.
It's extremely important that the helmet fits properly. Do not, repeat, do not buy one based on looks or reputation.
That said, you really can't go wrong with a Bell, Arai, Schuberth, etc. If the helmet is rated properly, cost doesn't make one helmet safer than another.
Like poster above said, consider your plans before buying. If you think you may need HANS in the future, buy accordingly.
Good luck and have fun at the track!
revster :: 08 e90 M3 jerez/black/carbon