I don't think that time travel is possible any more... The Delorian is broken. Wait, not really... all the component pieces of the Delorian are broken, but the car itself is perfectly fine, just not functional.
I realize the train still exists, I just felt like being an ass.
While I think the past would be cool to see fist person, I feel like I could get a fairly good idea of what happened by studying it. The future however is quite unknown, and would be cool to get a chance to see. The problem is that if you can't come back you wouldn't get to experience the future you would have had if you stayed. I have too many people and things I want to experience to leave this time and go see some totally unknown time. At least if I stay here I know I have a good chance of seeing stuff around me happen, if you go into the future even a few minutes too far you could totally miss any signs of civilization as we know it. 5 minutes after a nuclear war you arrive and see nobody, and then die from fallout. Five minutes after the last people die from drastic climate change, you see nothing and then die from starvation/hypothermia/heatstroke. Five minutes after the earth finally gets pulled into the suns gravitational pull, die. Obviously you could also arrive at some bustling metropolis or glorious peacefull planet, but with some of the options I think I'd rather find out what happens in my life if I stay here, it's still an adventure.