If functionality beyond ereading is important to you, consider the
best ereaders for apps and games and web browsing: iPad, Nook Color, Cruz R101, PocketBook IQ 701, etc. These currently tend to have LCD-based displays.
If the long-run text reading is most important to you, go with one of the
E Ink Pearl ereaders: Kindle 3 (WiFi|3G|DX) or Sony Reader (PRS-350|650|950).