I have had great luck with the Itead 3.2 displays (320X240) with an 8X8 character that is 40 X 30 lines, they can be had from Electrodragon, last time I bought one it was $16.50 and the Mega shield was $6.00 I also have a couple of the 2.4" displays and they work about the same. The library that I use is Henning Karlsen's UTFT Lib and it seems to be well thought out and versatile. I have one of each in front of me now, the 2.4 running a modified demo from the UTFT package and the 3.2 is running a GPS clock. The only real issue is that "natively" they are resource hungry (use a lot of I/O) which could likely be reduced with shift registers if an Uno was what you need to use. Mine are both on Mega's and one is on a 20 cm long 40 conductor M/F cable so I can access the board under the GLCD to connect the GPS receiver and the rest of the project as I develop the modules for it.
Bob