The Gold Standard of ascenders
I reserve the five star rating for very few items, but the Petzl Ascension Handled Ascender is worthy of it. This was an instant design classic when it first came out and has improved with various iterations over the years. These are the ascenders of choice if you are going to be doing lots of jugging as they are comfortable, secure and have a smooth action. They are ideal for Big Wall climbing, but I have also used them for Adventure Racing, Caving and cleaning routes.
About the only thing to watch on them is that the rope is fully engaged before you start fumbling with the trigger. Unlike other ascenders, with this one the rope is either in, or out - there is not threading, or halfway about it. This is good as it is secure, but if you are tired and not paying attention, the rope will pop right out when you thumb the trigger. Always tie a backup knot and never trust your life to one piece of equipment!