Years ago P. serraticauda was a very underrated Phelsuma. I know of a guy who traded a large group of them to get some Hemitheconyx caudicinctus when they were super rare, and incredibly expensive. Quite an ironic twist, huh?
It's only a matter of time before Madagascar either shuts its doors for good, or these geckos go extinct. There is little hope for most of us ever acquiring P. serraticuada or P. pronki amongst a myriad of others. It would be a damn shame, however, if the species we can still get today (lineatua, laticuada, madagascariensis, and quadriocellata) can't be found tomorrow because everyone wasted their time looking for "high end" species before securing what was already around.
This is not some rant against the market aspect of this hobby. This is going to happen again. P. guttata, klemmeri, barbouri, seippi, modesta, brevicepes, pusilla, serraticauda, flavigularis, standingi and mutabilis were all imported at some point (not to mention the species from the Comoros, Seychelles, and Mauritius) and now only a relative few, if any, of these are around today.
I just got reunited with this group over the weekend when I picked up some P. klemmeri females, and now I'm doing all I can to get whats around. You can't call yourself a Phelsuma keeper if you scoff off any species as being common.
So, you want my opinion on the most underrated Phelsuma? Any species you routinely see on kingsnake.com these days. That won't last forever (and not just Phelsuma, there are also other genera), and when the day comes when it's too late you'll be kicking your own ass for years to come.