General Antonyms:
* Spicy
* Flavorful
* Savory
* Zesty
* Tangy
* Piquant
* Intense
* Rich
* Full-bodied
* Interesting
* Exciting
* Stimulating
Antonyms Related to Taste:
* Sharp
* Sweet
* Sour
* Bitter
* Salty
* Umami
Antonyms Related to Personality/Style:
* Lively
* Spirited
* Dynamic
* Enthusiastic
* Passionate
* Bold
* Daring
* Original
* Creative
* Unconventional
The best antonym for "bland" will depend on the context in which you are using the word.