In English when we eat good food we say, "That was so good". In Japanese when we eat good food we would say, "That was so delicious". The word for delicious, or good in Japanese is oishii. To signify your gratitude for the hearty and delicious portions of o-konomiyaki, tako yaki, yakiniku, oden no tamago, sashimi, natto or especially the jewel like, mouth-watering, toro sushi you might eat in Japan, instead of saying the usual word for delicious, or oishii, try the following 5 Japanese words:
1. umai - very tasty, sweeeet.
2. bariuma - nice, tasty delicious, very good, superb, tastes awesome! - bari being the intensifier and umai meaning very tasty or sweeeet.
3. barioishii - same as in 1 above. - bari being the intensifier and oishii meaning delicious.
4. mechauma - an abbreviation of mechakucha and umai or the intensifier mechakucha meaning absurd, unreasonably sweet (or good, delicious) so mechauma would literally mean, absurdly delicious.
5. bakauma - baka umai - foolishly delicious.