hardcore sushi eater (and snob unfortunately) here.
try a softshell crab handroll (basically a
"spider roll" but in a handroll), or just branch out and try as many nigiri (fish on rice, not rolls) as you can and see what you like. get friendly with the sushi chefs and ask them to make you something with whatevers the freshest that day, or their personal favorites. tamago (egg) is a nice cheap filler that is easy to learn, hard to master. i generally get a softshell crab handroll, egg, white tuna, fatty tuna (if its in season), salmon, mackerel, unagi (eel) and then something new and random. hamachi can be good when its good, but usually most places have crappy ones (its cheap and a lot of people dont mind bad ones). good tuna should not be fishy tasting! nor mackerel, even though thats one of the stronger tasting ones.
when fatty tuna is in season (tuna season is late spring to early fall, but fall-ish is when they store the most fat so grab it then) the o-toro is stupendous.
my best advice - try and be as adventurous as you can, share with friends etc. youll slowly but surely find your favorites, then compare different sushi places by trying the same items as each place. soon you will be able to indulge and delight your tastebuds every time you go for sushi
enjoy!