I love the sketch where Ronnie C tries to disguise the fact that he's shat into one of Ronnie B's shoes at a cocktail party. Classic. 
Top 5 sketches 'of all time'? Page 3
New here and this seems like a good place to say hello!
Monty Python - Job Interview
Reeves and Mortimer - Masterchef
Snuff Box - Guitar Lesson
Fast Show - Johnny Nice Painter
Jam - Smart Pipes