When selecting a Rigol oscilloscope, prioritize Bandwidth and Sample Rate; ensure the bandwidth is at least 5 times the highest frequency of your signal to minimize error. Evaluate the Memory Depth, as a higher depth allows for capturing long periods of data while maintaining a high sample rate. For modern embedded systems, look for models with MSO (Mixed Signal Oscilloscope) capabilities to analyze both analog and digital signals simultaneously, and ensure the unit supports Protocol Decoding (e.g., I2C, SPI, CAN) to streamline debugging.