By default, Android-x86 boots to the command line instead of a typical Android GUI. This is great if you're installing Android-x86 to do wicked ninja hackery. I don't. I install Android-x86 to run Android apps. Colour me lamesauce.

Fortunately we can cajole such behaviour out of it by providing a UVESA_MODE argument to the kernel command line. Follow these steps:

1. At bootup intercept the GRUB menu by hitting the down key when it appears. Boot in Debug Mode.
2. At the command line, run:
   mount -o remount,rw /mnt cd /mnt/grub nano menu.lst
3. At the end of the first line that starts with kernel add nomodeset UVESA_MODE=1024x728 as shown (you will probably need to scroll right):
   default=0 timeout=6 splashimage=/grub/android-x86.xpm.gz root (hd0,0) title LineageOS 14.1-r5 kernel /cm-x86-14.1-r5/kernel quiet root=/dev/ram0 androidboot.selinux=permissive buildvariant=userdebug SRC=/cm-x86-14.1-r5 nomodeset UVESA_MODE=1024x768 initrd /cm-x86-14.1-r5/initrd.img title LineageOS 14.1-r5 (Debug mode) kernel /cm-x86-14.1-r5/kernel root=/dev/ram0 androidboot.selinux=permissive buildvariant=userdebug DEBUG=2 SRC=/cm-x86-14.1-r5 initrd /cm-x86-14.1-r5/initrd.img title LineageOS 14.1-r5 (Debug nomodeset) kernel /cm-x86-14.1-r5/kernel nomodeset root=/dev/ram0 androidboot.selinux=permissive buildvariant=userdebug DEBUG=2 SRC=/cm-x86-14.1-r5 initrd /cm-x86-14.1-r5/initrd.img title LineageOS 14.1-r5 (Debug video=LVDS-1:d) kernel /cm-x86-14.1-r5/kernel video=LVDS-1:d root=/dev/ram0 androidboot.selinux=permissive buildvariant=userdebug DEBUG=2 SRC=/cm-x86-14.1-r5 initrd /cm-x86-14.1-r5/initrd.img
4. Save changes and reboot:
   reboot -f

5. Boot with the first (default) GRUB menu entry. You should see a GUI style animated boot splash. The first time you boot with a GUI will take a very long time.
6. A more flexible way to implement this would be to create a second menu entry in GRUB:
   1. Copy and paste the first entry's configuration block (Control+U several times, Control+K to paste, if using nano)
   2. Add the additional kernel command line parameters to the first or second block, depending on whether you want to boot to the GUI or CLI by default
   3. Edit the title of whichever entry you have modified to reflect that it will boot into a GUI