Here are some things from off of the top of my head for the B5:
Xenon Gas Discharge headlights (package came with crystal clear corners, automatic headlight leveling system, and headlight washers)
Manual headlight leveling system via rheostat
Headlight Washers a la carte
Navigation System (came with Full-FIS cluster, options were a TMC box for dynamic navigation, TV-Tuner, and DSP sound system)
The natural Euro-switch
Gamma, Beta, etc... stereo head unit options, with DSP as an option (All radios including the navigation system were equipped with TIM, a traffic announcement function that recorded broadcasts of traffic news from certain stations.)
Telephone built into center armrest (this was able to be heard over the stereo, and microphone built into the dome light for speaking; in B5.5's if you had steering wheel controls you could answer the phone with a switch above the "Cancel" button and search through the phone's caller directory with the controls for the FIS cluster)
Heated Windshield (B5.5 only)
ESP was an option on the B5 body style, it was not reserved for the B5.5
Rear heated seats for the B5.5
Alcantara Leather seats
Recaro sport seats for the B5.5
Solar sunroof to power interior fans in the B5.5
The "anti-theft alarm system" (package came with interior motion sensors built into the rear reading lights and cancellation switch to the left of the driver; in B5.5's the infamous goose alarm horn was replaced with an alarm chirp much like the newer VAG vehicles)
The 9 engine options (not including W8 in 2003)
I had read somewhere that in South America, a power rear sunshade was available.
The clusters in Europe had built in service intervals that would be displayed when they were reached.
Rear Parking distance sensors (PDC)
There were five different variations of wood trim available, Net Optic was also an option.