Vinnie,
I can tell you that I myself have only had my Lynx for just over a year now. I have managed to amass quite a collection of Lynx games in that time. My must haves from my collection and from what I have played would be the following:
Xenophobe - I still need one!..but I have played it and love the lynx version!
Rampage - About the best port of the game I have found yet!
Paperboy - Easier than any other version I have played...hence why I like it!
CyberVirus - Forhan's Homebrew masterpiece! Gotta get this one!
Gates of Zendocon - slow paced shooter...but can get tight at times.
Rygar - Classic platform action
Shadow of the Beast - I don't care that it is hard...it is simply gorgeous to look at!
That is what comes to mind right now...I do on occasion like to pop in Crystal Mines 2 and Toki.
Many also consider Warbirds to be a must have. While I do think the mechanics of the game are impressive in that it is basically a true 3D enviroment you fly around in...the single player portion of the game just doesn't keep me going. I am told Warbirds is best com lynxed anyway.
I also would like to find me a Slimeworld someday as I have played that in emulation and really like the game.
As for Basketbrawl, the general concensus is thus:
7800 version - tolerable
Lynx version - SUCKS!!!
Hope that helps you out Vinnie!