An adjustable Wahl with oil and a cleaning brush. Not rechargeable; cord or batteries are better. Metal is always better than plastic. Heavier is better. A mustache comb and a beard brush would complete the kit, and are often included.
Oster and Sunbeam, not so much.
Also, just because the world is weird now, make sure you get a BEARD trimmer, not a BODY HAIR trimmer.
- Ron | samwisekoi