diamonds I have to disagree with you. I'm finding Ashes to Ashes to be so much better than Life on Mars. In LOM Sam Tyler is so serious and intense the only comedy comes from The Gov and his totally Un-PC staff. In ATA Alex's acerbic wit is hilarious. ie: walking into the squad room : "Good morning constructs" (FYI she knows that the entire crew are constructs of her sub-conscious thanks to Sam Tyler's detailed notes)
LOM is set in 1973 - with way better music. ATA is set in 1981 with the beginnings of punk.
I highly recommend both series.