I've never had any that tasted like chicken but beware that most if not all sushi is made with wasabi paste which is kinda like horse radish and will make your nose burn and your eyes water. Other than that it's delicious especiailly the big red salmon eggs.
White tuna is amazing. If you've never tried it, go to a real japanese rest, and tell them, you've never had sushi before and can they recommend something to you. Figure on around $20 to $30.00 for a better selection. A little washbi and soy and just dip and pop in your mouth. You'll thank me later.