What to do about Crazy?

This cat is driving me nuts!!!! He walks around the house meowing and hollering like crazy! He often sounds like a baby yelling! Plus if that isn't bad enough....he has decided to start marking his spots!! If ya know what I mean? I haven't actually found the spot where he marked to be "his" but I sure do smell it!! YUCK!!!!! I have washed and washed and can't seem to get rid of the smell! How can I stop him from calling to his girlfriend at all hours of the night and marking his spot?? He is a house only cat and so he has the run of the house, what should I do??
Will getting him "fixed" make the spraying and crying stop?? Our Animal contral has a thing where you can get them fixed for $15.00 but I don't want to do that if it isn't going to stop the problem. What should I do??