I prefer Nolan brand.
The full face has the front that lifts up. Easy on/easy off. The N103 and higher have an inside drop down sun visor.
I have three of the above
For 3/4 version (N/40/N43/N44), They have inside drop down sun visor and optional use chin bar, as well as full drop down face plate.
Also have three of these.
Motorcycle Superstore has the full line up. See their site for pictures and more complete descriptions.
N44 on the left, N104 in the middle, N40 (no chin bar) on right
EDIT: I posted this information in another helmet thread yesterday--but will add it here since the subject came up below.
Fit, fit, fit, is the most important part of wearing a helmet. You mentioned that you are stuck with buying by mail. A very good idea if possible to go to motorcycle dealers and try various name brands, and see how their sizes match with your required fit. Different brands are never the same when it comes to sizing. If you cannot do the dealer check out, then make sure you can return or exchange the purchased helmet in case you need to. Most larger suppliers have this policy.
Dealers usually charge more than internet helmet providers, but the personal service and sizing is important. Most dealers can get you the color/size you need within a week--if they do not have exactly what you want in stock.