Well, let's do a little run down:
-I helped name my brother Sam, as at the time I was obsessed with Green Eggs and Ham, without me, if he's even born, he'll have a different name.
-My girlfriend has told me several times if I didn't date her, she'd be drinking and doing hard drugs (and addicted) like several members of her family at one point.
-I introduced my girlfriend's brother to his boyfriend, my best friend to his girlfriend, and help two other friends when they were still in the pursuit of the person they are currently dating.
-Two of my online friends cited me as a person who helped them get out of strong bouts of depression.
-A somewhat minor trollfic would not exist.
-Half the people I know wouldn't be nearly as into Batman or Rush.
On the flip side however:
-I would have never introduced my dad to World of Warcraft, preventing the chain of events that lead to their divorce.
-A relatively small internet forum dedicated to gaming would still exist (I pretty much unintentionally killed it).
-Without me being an easy target for bullying in middle school, another student might have gone down a (slightly) better path in life, (possibly) preventing his eventual murder.
-The first band I was ever in doesn't create two of the worst songs ever recorded(with me on vocals).
-Lockport's mayor is quite possibly primaried in 2011 (it was incredibly close, before they got absentee ballots it was just 2 votes in his favor). He nearly lost to a slightly crazy old lady in the primary. This would have ensured victory for his opponent, who in all fairness was probably better.