If you’re asking which I prefer for a more complete browsing experience, I prefer Elinks. It has tabbed browsing, download/password managing, and tabbed navigation (handy when in a terminal). It also (partially) supports CSS 2.1, (fully) supports frames. It also (partially) supports JavaScript. Not as important, but Elinks supports more protocols than Lynx (I specifically use the Bittorrent protocol).
If you’re asking which is more suitable for testing text-only browsers, Lynx is probably more popular, but Elinks is still a great choice here as well.
For comparision look here.