Both Agilent (formerly Hewlett-Packard) and Tektronix build good oscilloscopes. The Agilent has a higher bandwidth, which is desirable, and variable persistence which is useful for viewing low frequency signals, short low rep-rate pulses, or capturing single-shot waveforms. So assuming they are in comparable condition I would probably go with the Agilent.
Have you considered getting a digital oscilloscope? They have many added measurement features that analog scopes don't have.