The ones that are filled with meatballs, really thin rice noodles, vegetables, herbs and wrapped in round sheets of rice noodle. They're great, especially in summer. However one time when I ordered them it turned out to be a "roll your own" platter. The staff must have had a good laugh at my performance afterwards. :( How the hell do you fill them without tearing the sheets to shreds, and then keep them together while you dip them and eat?
2GET
The roll with sliced boiled pork, shrimp, noodles & herbs is better, the taste's more delicate and delightfull cause you will able to enjoy the individuals taste of ingredients mixed together, better than the meatballs smell takes all the spotlight. (the kind of roll is called "goi cuon"
Try to order "banh xeo", which you have sthng like crepe' but shrimps, pork & vegetable added, then wrapped the berb inside (incontrast to the way you wrap the aboved dish), dip in same source. (quite funny as it's just like the California roll out compared to sushi ^^)
The trick is to not overstuff them. They are extremely fragile and a pain in the ass to work with, and you can't just roll it up like any old burrito. The way I've always done it is put the filling on the first third of it, roll up the side, then the bottom, then roll the rest. While eating hold it all together with just your fingertips.
use double rice wrap instead of single one. It's then the duel for your teeth trying to chew the roll :))
Here's the secret but ignore the ingredients in this one...
http://vegetarian.about.com/od/cookingtipstools/ss/Howtospringroll.htm
You have opened mine eyes. I see now I had been overstuffing them so much I could barely get a finishing overlap of 1/2 circumference, never mind the 2 or 3 shown there.