I take public transit because I have no choice.
Public transit was created as a form of torture to the environmentally friendly and those who can't afford to drive cars. While the majority of people who ride on buses and trains are just like you and I (poor souls that just want to get to and from work / school), occasionally you may come across vagrants or surly teenagers. It's a dog eat dog world on public transit, but if you follow these simple tips, you'll live to see another day, another bus ride.
Pick the best spot -- The key to a "good" bus ride is the seat that you choose. If you choose wisely, you may have a quiet, semi-pleasant bus ride, if not, you might have the worst experience of your life. Riding at the back of the bus is a solid choice; it's not as crowded, but you have to deal with the bus fumes. If you're feeling lucky, aim for the middle of the bus so that you can dash off through the back doors as quickly as possible if needed.
Be suspicious.. very suspicious -- Sadly, in today's time you no longer can leave your doors unlocked or let your children play alone in the yard. The same rings true on public transit; everyone is a suspect. See that little ol' lady sitting across from you? She's eyeing your purse. Keep your valuables close incase she decides to spring up and dash off the bus before you have time to say, "Hello, Grandma".
"Hello craziness, my old friend.." -- It's best to avoid having others sit next to you on public transit. That way, they can't slip their hands into your pockets while they sweet talk you. The easiest way to deter people from sitting next to you is to act crazy. Start looking frantically around the bus, muttering under your breath, and periodically burst out singing in a foreign language (made-up language is okay too). Be careful though - you might attract other lunatics this way.
"I'm starting to feel ill.." -- If it's unavoidable that someone must sit beside you, you can easily solve this problem by groaning in pain, holding your forehead and fake coughing. People HATE the thought that someone could get them sick, and will most likely move to another seat. If you're got a sticker (a rider who refuses to move), be bold and ask them if they have a bag that you can be sick in. Problem solved.
I spy.. -- If none of these tricks work, you may have to suck it up and sit beside someone else. In this scenario, play a game that will entertain you until the ride is over. My personal favourite is counting the lice in the hair of the in front of me, or predicting how long it takes for the bus driver to come to his senses and abandon the bus.
Congratulations! You've survived to ride another day..