I don't even like DSOs but I would also say Rigol.
If you ever have cause to look for low frequency noise,like hum,on a high frequency signal,you will appreciate
larger memory depth.
DSOs without much memory depth lower their sampling rates as time/div is increased,with resultant aliasing
problems.
A classic,standard test at TV stations was to look for hum,clamping error,etc on an analog video signal.
Even the early (1990s) DSOs from such illustrious firms as HP & Tektronix failed this test.
I don't have a Rigol,but from what I've read on this forum,it would pass.
If all you will ever do is look at signals at or around their period,maybe the UN-T would de adequate,but you may
find your requirements change.
Or, you could buy a secondhand Tektronix analog Oscilloscope,unless you really need all the DSOs "bells & whistles".
VK6ZGO