More powerful pedelecs which are not legally classed as bicycles are dubbed S-Pedelecs (short for Schnell-Pedelecs, i.e. Speedy-Pedelecs) in Germany. These have a motor more powerful than 250 watts and less limited, or unlimited, pedal-assist, i.e. the motor does not stop assisting the rider once 25 km/h has been reached. S-Pedelec class e-bikes are therefore usually classified as mopeds or motorcycles rather than as bicycles and therefore may (depending on the jurisdiction) need to be registered and insured, the rider may need some sort of driver's license (either car or motorcycle) and motorcycle helmets may have to be worn. In the United States, many states have adopted S-Pedelecs into the Class 3 category. Class 3 ebikes are limited to <=750 watts of power and 28 mph.
I wanted to include an electric bike that would be ideal for off-road and trail bike touring, and I think the Bulls E-Stream Evo 3 27.5 Plus is it. This hardtail mountain bike would be perfect for bike tourists going out on the trails for a few days. You could conceivably go for a few days without needing to recharge the Brose 650 watt hour battery, so even if your camping in the wilderness with nowhere to recharge for 60-100 miles you would likely be fine on battery life.
Everyone seems to know a lot about Haibike’s e-MTBs, but I think their commuting and touring bikes are just as good, if a little bit underrated by the e-bike community. Another bike with the Bosch speed motor, this bike is quick and powerful. I really like the spec upgrades on this bike from the Trekking speed model in 2017. You’ve got Magura MT4 hydraulic disc brakes, a Shimano Deore XT M8000 Shadow Plus drivetrain, and the headlight and taillight run off a dynamo.
E-bikes mostly use motors and battery options from a few major suppliers: Bosch, Yamaha, Shimano, and Brose. A few other brands exist, but are less reliable or powerful. Some, like the Yamaha system, have more torque and others are quieter. But generally all four make good options. Look for motor output (in watts) which will give you an idea of total power. But watt hours (Wh) is perhaps a better figure to use—it takes into account battery output and life to give a truer reflection of power.