Positive:
* Ardent: Intense, fervent, passionate
* Burning: Fiery, intense, passionate
* Fiery: Full of passion, intense
* Fervent: Very enthusiastic, passionate
* Intense: Strong, powerful, passionate
* Rapturous: Full of joy and excitement, passionate
* Zealous: Full of enthusiasm and fervor, passionate
* Enthusiastic: Full of excitement and interest, passionate
* Driven: Motivated, determined, passionate
* Inspired: Filled with creative energy and motivation, passionate
* Committed: Devoted, dedicated, passionate
* Invested: Deeply involved and committed, passionate
* Eager: Very interested and excited, passionate
* Exuberant: Full of energy and enthusiasm, passionate
Negative:
* Fanatical: Excessively enthusiastic or zealous, sometimes dangerously so
* Obsessive: Preoccupied with a single idea or person to an unhealthy degree
* Unbridled: Uncontrolled, unrestrained, potentially destructive
* Unhinged: Mentally unstable, potentially erratic
* Consumptive: Wasting away with passion or longing
* Destructive: Causing harm or damage, potentially due to intense passion
* Blind: Lacking reason or judgment due to strong passion
Neutral:
* Strong: Powerful, intense, passionate
* Deep: Intense, profound, passionate
* Unwavering: Steady, resolute, passionate
* Unquenchable: Impossible to satisfy or extinguish, passionate
* Unrestrained: Free from control or restraint, passionate
* All-consuming: Engulfing, consuming all attention and focus, passionate
Specific to certain areas:
* Artistic: Passionate about art, music, etc.
* Romantic: Passionate about love
* Intellectual: Passionate about knowledge and ideas
* Political: Passionate about social and political causes
* Spiritual: Passionate about religious or philosophical beliefs
The best adjective to describe passion will depend on the specific context and what you want to emphasize.