You need to clarify the difference between bandwidth and sample rate. For example, the PropScope is 25 million samples per second. It will barely be able to accurately digitize a 5 MHz square wave.
The Rigol is an awesome deal if you can get the hack going (see the mega thread on www.eevblog.com). I have a DS1102E that didn't need the hack, and it's a good scope.
The Link MSO19 you will outgrow very quickly. It has a single analog channel and cannot measure signals much below 50 mV
The best scope for me right now is the QA100 because it has logic analyzer built in. It has 100Msps sample rate, 25 MHz bandwidth, and 12 or 16 logic channels (can't remember). And $350. The Rigol scopes don't have any logic channels in the base unit. You can add them, but the scope price isn't very good anymore. In fact, it's outright expense.
The QA100 also has protocol decoding. I can't imagine any engineer today not needing even a simple logic analyzer with protocol decoding at some point.