acpi=off: Disables ACPI which is used for power management and actually turning off power after the shutdown. This may help with compatibility with motherboards which misuse ACPI.

noapic: Disables Advanced Programmable Interrupt Controller. This is used to resolve hardware conflicts for interrupts, but may itself cause a conflict. Use of this option may disable some hardware that enters a conflict without an APIC.

nolapic is very similar, but disables a different (newer) kind of APIC called a LAPIC(Local Advanced Programmable Interrupt Controller)

edd=on enables the EDD probe(Enhanced Disk Drive), used by motherboards to provide more functionality to disk drives

nodmraid disables dmraid which is used for RAID purposes but may cause empty disks to appear even if they are fully partitioned, possibly with the wrong size.

nomodeset keeps the video driver from performing modesets which are used to bring the graphics card to an enhanced state, but due to incompatibility, may cause display issues.

Free Software Only is used for legal purposes and will not load restricted drivers or codecs. Use if your jurisdiction disallows the use of restricted software without a license and you do not have one, or if you do not prefer to use closed-source or restricted components or code on your system. Certain codecs or hardware may be unusable.

https://help.ubuntu.com/community/BootOptions#Common_Kernel_Options has a few other options.