Your question has no answer.
If one was better than the other only one would exist.
A logic analyser and an Oscilloscpe are different instruments used for different purposes.
Tektronix make a few combined logic analyser/oscilloscope you may want to check out.
But in deciding which of the two is better, you have to understand what it is you want to measure, the one which is 'better' depends on what you want to measure/observe.
Added after 10 minutes:
zeeshanzia84 said:
well i guess by digital oscilloscope, companies don´t only mean that it samples and digitizes the input signal.....usually it will also have a digital display...and a built-in microprocessor to control everything....which means that they definitely will be placing some extra functions like displaying the frequency, mean, pk-pk, etc values.... which is really great....provided u´re comparing two equal BW instruments (of course i guess the cost is going to be greater)
on the other hand....the analog oscilloscope IMO, will not only be analog in the sense that it doesn´t digitize the signal (using ADC)...but also that it has an analog display....and no microprocessor....so no direct Frequency, Mean Voltage, Pk-Pk voltage display....which is definitely an inconvenience....but i think it will be at a lower cost for the same BW instrument.
hope this helps.
Most (if not all) analog scopes display pk-pk, frequency information etc. And loads of them have math's functions to plot average values, FFT's, A+B etc. A logic analyser will not tell you this, it will giver you the transition times, but not voltage information. To look at analogue waveforms a Oscilloscope is the tool to use (of course Scopes are all digital, but they display an analogue response).
I'm not sure what you mean about an Oscilloscope not having a voltage display, that is what they do!!