It depends on exactly what you are going to do with the scope! TEK scopes are good and pretty reliable, HP are ok, lecroy good, the others are 2nd tier.
If you are a ME and want to use it in mechanical work, like robotics, you are going to need to sampe slow moving stuff. Therefore, make sure you get a digital scope with sufficient record length memory to see your waveforms.
If you are an audiofile, a good 100 MHz analog scope would be fine.
If you are an RF guy or ham, you probably want the fastest Analog scope you can get to see the rf waveforms (you can see them on a digital scope too, but to do so you need a very high clock rate that you probably can't afford, even used).
If you are going to be doing a lot of microcontroller work or digital electronics, you want a digital scope, or maybe even a logic analyzer instead.