Everyone will have their own favourites/opinions but.....
Well, if it's leather then Meguires cleaner/conditioner (in one) using a terry towel.
If it's cloth then I use as wet+dry vacuum shampoo'er machine on seats and carpets.
Plastics = Armourall 'matt' dashboard cleaner (i don't like the shiney dash look).
Door rubbers = Autoglym bumpercare gelly.
Roof lining - err, dunno really but maybe a spray/brush foaming upholstery cleaner can thing? (I've never done a roof properly, not needed too, but it's certainly strange material).
Top tip - clean the pedal rubbers with an old terry towel with just warm water - makes a huge difference to the look.
Top tip - use a soft brush hoover attachment to vacuum around the facia/switches and air vents.
Finally, some Autoglym Odour Eliminator on the carpets and in the boot.