I loke the big finish audios. They are a good way to get a doctor who story fairly quickly with pacing very similar to the old show. Since Big Finish has allowed Download purchases of their line I have been trying to catch up slowly but surley.
they great thing about the audio adventures is that they can side step into things that you have always wanted to see, like spin off series with the daleks, cubermen, and unit. These series are all very neat and come from a different angel. You get to hear secret origens that you haven't gotten before. There are some great adventures.
So for those of you who arn't familiar with the line here is my guide to some very good stories (or seires)
Holy Terror: Written by Rob Sherman (the writer of "Dalek") this story takes the doctor to an unusaul midieval style kingdom, but who is really the ruler. This story also puts the 6th Doctor with Frobisher his shape shifting companion from the DWM Comic strip.
Spare Parts: This is a origin story for the cybermen. This is the fifth Doctor pitted against the original style cybermen. Nick Brigs does some great voice work here.
Dalek Empire: There are four series of this (each with atlest 4 disks). This is a story about the daleks. No Doctor. Just the daleks conquring. It is s a throw back to the old TV Century 21 comic strips of the 60s. Written by Nick Briggs who also voices the daleks in all of the audios AND on the TV series.
This is where I sugeset to start. These are some of my favorites, but there are many others. It is such an extensive line that you really need to jump in and see what you like, but here are some starting places.