I kind of like the stuff here:
Onboard or offboard USB/serial adapter, dual hardware UART with RS232 buffer option for 2nd UART, area for a DIP chip or SMD to DIP adpater, or RF module (nrf24L01+, or simple 433 MHz Rx or Tx module), option to add screw terminals for tight connections, shield header, pins duplicated for easy connections or probing, +5/Gnd on every pin, SD card for data options, 128K flash, 16K SRAM, 4K EEPROM, power options, battery backed RTC with 56 bytes of 'NVRAM'.
And of course, IDE supportable (requires /variant folde addition:
http://forum.arduino.cc/index.php?topic=235521
Some might call me biased tho 8)
http://www.crossroadsfencing.com/BobuinoRev17/
