The first worst way to wake up is quickly, not because the act of getting up quickly may result in neck/back pain, but because having to wake up quickly generally means there's a reason for it. Sure, your inital waking may be slow and controlled, but when the clock reads 9:15 and your final exam started at 9, that changes. Your sense of awareness goes out the window as you panic, trying to remember where you have to be, what you have to do, and why oh why can't the alarm wake you up in time? (Note: Often results in having to run to class with minimal required clothing and not having showered.)
Other reasons for this include being jostled awake by a loud noise or phone call, leaving you scrambling because you have no idea what happened or where the phone is.
2. From a nap (only if you wake up in the evening)
This only happens if you wake up when the sun is starting to fade. Results in initial shock caused by the fear that you've actually slept through the night and that it's now morning. Generally followed by relief when you see what time it really is.
3. In the middle of the night
Leads to massive disorientation, followed by the realization that you can either attempt to fall back asleep, thus turning your sleep into a nap, or you can just stay up and get through the day. Often is the cause (or result of) massive alterations to your sleep cycle.