The wheels on the bus go round and round......

I'm going to keep this short and sweet.  I took the bus from D.C. to NYC and back during Memorial Day weekend.

Pros:

Super cheap.  Memorial Day weekend prices were $30 each way.  I have been told that during non peak days, you can get tickets at around $20 or so each way.

It is nice to let someone else do the driving.

Cons:  (mostly #firstworldproblems)

WiFi is advertised as free, but in reality, it is non-existent (super slow @ 56k speeds and connections drop all the time).

Seats are super cramped for a 4 hour bus ride (would be better for shorter rides).

Although it is nice not driving, you still need to deal with traffic jams that will delay your arrival time by more than an hour.

Conclusion:

The bus from D.C. to NYC is good for short trips during off hours when traffic is light.  It is also great for when you have a lot of time to kill.  My bus arrived to pick me up an hour late each way due to really stupid reasons.

After talking to seasoned travelers who frequent NYC from D.C., they recommend the train.  With the train, you pay a little extra but you don't have to deal with traffic jams, have plenty of space (even in coach), and apparently their WiFi connection is not bad.