Not pathetic at all.
When I went to bars I would have the best time going alone. Going with friends would be cool too but if you are wanting to meet someone then alone always seemed easier since people seemed to assume I was dating my friend.
Not bar related but here in Austin there is The House of Torment.http://www.thehouseoftorment.com/
I went alone both on Halloween night for the haunted house and again the weekend after to Darkstalkers. As anti-social as I have become lately I seemed to not have any problems talking with people in line. I kept getting told in line for Darkstalkers that I am very brave since I was going in by myself. LOL Good thing I don't scare easily.
But anyway about the bar scene here is how I used to handle it.
1. Be nice and tip the bartender you chose well. They will remember you and if anyone happens to ask him about you he will talk good about you. He may even warn you if he perceives trouble coming your way. Start with "How are you? I'd like a ." If he is friendly then have him as your bartender but if not then tip normally and go to another.
2. Don't stand near a wall. If you are going to stand anywhere make sure it is lit and stand tall and confident even if you are not. If you are one to move with the music do that (unless there is no dance floor) and you may get asked to dance. Just don't stand in the way of where people normally walk and don't stand in one place too long. Just because you are alone doesn't mean you have to be lonely in a crowd.
3. Make eye contact with everyone but not stalkerish and not like you are attracted to them. Just because you don't find the guy attractive doesn't mean he might not have a hot friend.
4. Talk to anyone that instigates a conversation. Doesn't matter how old or young they are. There is nothing wrong with having bar acquaintances. You can always make excuses and get away from them if you need to.
In other words if you are friendly enough and nice enough to everyone then the club could become a great place and it wouldn't matter if you go there alone or not. You will always have someone to run into that you have met before.
Hope this helps