If you're using JBoss 4, I'd recommend JBossWS.
If you're not using JBoss 4, I'd recommend upgrading to it and using JBossWS. ;)
Seriously though, JBossWS is J2EE 1.4 standard and fairly straightforward to use when you get your head round it.
I've used both JBoss.net and JBossWS and much prefer the latter.
Thanks for the flowers ;-)
BTW, JBossWS passes > 2200 tests from the J2EE CTS