Hi Woodsy,
I've given this some thought .......

Top 5 :
1. T3331520 : Gear Change Pedal & Rear Brake Pedal Pivot Bolts
2. Rear Suspension Wishbone Bearings, Seals & Ground Sleeves. ( Multiple Parts )
3.
Clutch Slave Cylinder Repair Kit4. T2025056 : Front Dscs ( x 2 )
5. Electrical Relays : 2 types - T2506035 - Changeover Relay ( Total 4 ), & T2506040 - Relay ( Total 6 ).
Other "Good to have" parts :
T2022395 : Front Brake Pad Kit ( x2 )
T2021228 : Front Brake Pad Pin ( x 4 )
T2022397 : Front Brake Pad Spring( x 4 )
T2022391 : Front Right Caliper Piston & Seal Set
T2022392 : Front Left Caliper Piston & Seal Set
TT2450GG : Rear Brake Pads
T2020966 : Rear Brake Pad Pin Set ( 2 )
T2020954 : Rear Brake Pad Spring
T2020050 : Rear Brake Caliper Piston & Seal Set.
T1218001 : Oil Filter
T3331400 : Sump Plug Washer
T2204925 : Air Filter
T1290181 : Spark Plugs ( NGK3478 / CR8EK ) x 3
T3800703 : Front Wheel Bearings ( x 2 )
T3600701 : Front Wheel Bearing Oil Seals ( x 2 )
T2002105 : RH Front Wheel Spacer
T2002100 : LH Front Wheel Spacer
T3800062 : Rear Wheel / Final Drive Bearings and Seals
T3800420 : Rear Wheel / Final Drive Bearings and Seals
T2309082 Right Bodywork Protector ( Mirror Rubber Bumper )
T2309083 Left Mirror Rubber Bumper ( Mirror Rubber Bumper )
Pannier & Top Box painted covers
T3351111 : Fairing Captive Boss Fixing ( Battery Cover & Glove Box )
Various Rubber Grommets :
Side Panels
Glove Box & Battery Cover
Front Indicator Surround Panel
Front Wheel Arch Side Infil Panels
Fairing Side Infil Covers
Fairing etc Button Head Hex Screws ( M5 x 16 and others )
Cheers

