This is my /etc/default/grub file, and this is how I got my GRUB 2 boot menu to display by default with Linux Mint 12. You just need to add the GRUB_HIDDEN=0 line to the menu and ensure the rest of the file looks like my example and the menu will be accessible by default without having to press the ESC key within the first seconds of the boot sequence. This was quite a simple fix, I was just guessing when I tried this fix, it was something I assumed would work and it did. This should work just fine with Ubuntu as well. A handy fix if you are dual-booting and you want to select which operating system to load easily.
# If you change this file, run 'update-grub' afterwards to update # /boot/grub/grub.cfg. # For full documentation of the options in this file, see: # info -f grub -n 'Simple configuration' GRUB_DEFAULT=0 GRUB_HIDDEN=0 GRUB_HIDDEN_TIMEOUT=0 GRUB_HIDDEN_TIMEOUT_QUIET=false GRUB_TIMEOUT=10 GRUB_DISTRIBUTOR=`lsb_release -i -s 2> /dev/null || echo Debian` GRUB_CMDLINE_LINUX_DEFAULT=" " GRUB_CMDLINE_LINUX="" # Uncomment to enable BadRAM filtering, modify to suit your needs # This works with Linux (no patch required) and with any kernel that obtains # the memory map information from GRUB (GNU Mach, kernel of FreeBSD ...) #GRUB_BADRAM="0x01234567,0xfefefefe,0x89abcdef,0xefefefef" # Uncomment to disable graphical terminal (grub-pc only) #GRUB_TERMINAL=console # The resolution used on graphical terminal # note that you can use only modes which your graphic card supports via VBE # you can see them in real GRUB with the command `vbeinfo' GRUB_GFXMODE=1680x1050 # Uncomment if you don't want GRUB to pass "root=UUID=xxx" parameter to Linux #GRUB_DISABLE_LINUX_UUID=true # Uncomment to disable generation of recovery mode menu entries GRUB_DISABLE_RECOVERY="true" # Uncomment to get a beep at grub start GRUB_INIT_TUNE="480 440 1"