Dishonest/Unfair:
* Devious: sly, cunning, and deceptive
* Corrupt: morally tainted, dishonest
* Shady: suspicious, dubious, untrustworthy
* Fraudulent: deceitful, intended to cheat
* Rogue: dishonest, untrustworthy, rebellious
* Duplicitous: deceitful, hypocritical
Bent/Not Straight:
* Askew: not straight, tilted
* Bent: curved, not straight
* Twisted: deformed, contorted
* Skewed: tilted, lopsided
* Warped: deformed, twisted
Other:
* Unethical: morally wrong
* Unfair: unjust, biased
* Unprincipled: lacking moral standards
* Dishonorable: lacking integrity
* Inconsistent: not reliable, unpredictable
Please provide more context about how you're using the word "crooked" so I can give you a more precise suggestion.