I'd definitely say VAG-COM... very critical for the average DIY'er for diagnosing or customizing various things (airbag light, ABS light, anything engine related, anything transmission related for those with auto trannies, central locking module coding, etc.).

 

everyone would be wise to buy a decent compressor and decent air tools. an air hammer and 3/8 and 1/2 inch impacts help a lot. a skinnyish set of allen sockets are necessary. a 17mm allen socket for front cv axles and tranny fill plug. multiple hammers

 

I lol'd but that's very true. A 6-8lb dead blow is a pretty good size for suspension work and other jobs that require controlled violence.