To me, they fall into two categories, and the one is pretty much dominated by SunRay. That is the in-line pinpointing probe.
But for hand-held, stand alone electronic pinpointers there have been some good ones, like the White's BullsEye or Vibra Probes, some lesser versions like the Centech and many others. Some that were better in performance, like the Treasure Mate, built by Tesoro, that requires manual tuning but gives decent depth. Detector Pro has provided us with a couple of top performing (for depth) designs, too, but they are either too expensive for some, or too bulky
I haven't been a big fan of pinpointers due to either poor depth and performance, cheap construction or bulk/awkward physical design. I always felt if there was a decent hand-held pinpointer that provided me good functional depth in a comfortable hand-held design that was durable, I'd own one and use it.
My detector battery is made up of White's models, modified or stock, and one low-cost Garrett ... the Pro-Pointer. It is the best quality constructed pinpointer on the market. period!
Monte