We'll break this down into a few categories: best automatic handheld leaf trimmer machine, best bowl type trimmer, best wet and dry trimmer, best wet trimmer, best dry trimmer and best trimmer for kief collection.
For all the wet and/or dry categories, we'll give you the top options for different capacity levels, so you can choose the one that can handle your workload.
If you do not have a large operation that needs to process tens, hundreds, or even thousands, of pounds of bud per day, you probably don't need anything larger than one of the manual trimmer models.
When it comes to manual electric leaf trimmer, you really have two options. A bowl trimmer or a handheld automatic trimmer.
Note: If you are just looking for a pair of manual trimming shears, I recommend this pair on Amazon. They are inexpensive, but good enough to get the job done, and that's really all I need from shears.
The Magic Trimmer is great for complete manual hand trimming. If you employ human trimmers, or you simply trim smaller amounts of buds yourself, it will considerably speed up the process over using shears to remove leaves.
This hand trimming machine has advantages over the large trimmers below, too. Since you control it manually, it is much more precise. You control exactly what is trimmed off the bud and what stays, giving you nicer trimmed buds. It is also compact, lightweight and inexpensive.
The main disadvantage of this trimmer is obvious. Since it needs to be controlled by a person, it has a limited capacity compared to an industrial bud trimming machine.
Using the magic trimmer is easy. The patent-pending design ensures no possibility of injury. Since you have full control, it is extremely precise, while being much faster than using regular shears.
Pros
Low Price: selling for $349 at the time of writing, compared to thousands for the machines listed below
Compact: trimmer fits in your hand
Lightweight: 2.5 lbs. makes it by far the lightest trimmer on this list
Precise Control: manual operation means you have full control over what leaf material gets removed and what stays
Cons
Capacity: it can't come close to the capacity of the larger trimmer machines on this list
Best bowl trimmer
Simply fill the trimmer with bud, close the lid and turn the hand crank. The 30 shears do all the work for you. If you get one of the motorized models, you don't even need to do any hand turning. Just fill with bud, turn it on and let the cutting blade do the work.

These bowl leaf bowl trimmer canada work best with wet bud. They do a good job, but are not as precise as the handheld unit above. They also don't give as good a trim as a larger bud trimmer machine like the ones below. Their capacity is obviously much lower as well. Some do have adjustable blades for more precise cuts.
Pros
Low Cost: a few hundred dollars instead of a few thousand
Small and Lightweight: take up little space and even the motorized trimmer models only weigh around 20 lbs
Cons
Capacity: can't compete with a real bud trimmer machine
Quality of Trim: they get a good trim, but not as good as a larger bud trimmer machine and definitely not as good as manual bud trimming