Talk about solving a problem that doesn't exist
If you find you are often waiting around and others are getting served ahead of you, ask yourself:
1) is the male bartender serving others ahead of me because they're cute girls, and I'm not?
2) is the female bartender serving others ahead of me because my "flirting" comes off really creepy to her?
3) do I have a reputation for ordering complicated drinks that take a long time to make, or complaining they weren't made to my lofty standards?
4) if in the US, do I rarely or never tip?
If you answer those questions honestly, you will see the reason why you are always served last. Most bartenders want control over the order they serve people, and would resist a computer telling them who to serve next. They will keep serving you last until you correct these behaviors.