So I know Megabus usually gets a lot of hate, but I can honestly say they have never let me down. I have been on enough of these to say with confidence that as long as you understand you're not paying for a luxury experience, you should have a fine time.
Here is the deal, you're paying anywhere from $1 to probably around $45 to travel pretty substantial distances which normally would cost a fortune in gas. So sometimes they are an hour late or the wifi is shotty, what were you expecting? As long as you go into your Megabus experience understanding that you get what you pay for, you really shouldn't have anything to complain about.
I have taken Megabus probably at least 25-30 times and I have always reached my destination on time and fully in-tacked, and for $1, what more can I ask for?