I admit that I play very careful and cautious.
my greatest satisfaction is after hitting a convoy at night to escape at 120m without being detected by any ASW-vessel.
as many do, I hunt during day-time and attack at night. though I play 76% realism-settings and therefore it's way easier to track the convoy and gather the needed informations, I get a lot of excitement out of SH3.
the most thrilling approach is (when approaching submerged from AOB90) to let the lead escort sail by and then sneaking into the first two lanes of the convoy without being detected by the side-escort which by now is already at 150-210degrees in your back. nerve-wrecking!!
for taking out ships I prefer: one aal = one sinking.
I like rough seas which is an enormous help with killing vessels by bow-hits. the thrust of the engines even more push them under water.