I like the vegetarian ones with the nice sesame. Don't know the name.
Sounds like those nigiri sushi with wakame.
Was it kelp-like? If it is, it should be wakame.
Anyway, to me, salmon or tuna should be nice.
But after you go to Japan and try their Tsukiji market standard type of sushi, it won't be the same and you won't have so much zeal for sushi in your own country.