We have lived in West Norwood for the last seven years and are really happy here - so much so we have just sold our first place and bought a new house 2 streets away! Would agree with previous comments about living at the Gipsy Hill/Streatham Common end though - the Tulse Hill end is definitely not as nice.
There are lots of things we love about it. Commuting from here to work in central London is super-easy - 20 mins to Victoria, 25 to London Bridge, 4 trains an hour to each and you can pretty much always get a seat in rush hour. The houses are actually affordable - we own a nice 3-bed semi on a nice road with a biggish garden for what you would pay for a 1-bed flat in Camden. There are loads of green spaces within walking distance - we are right next to a park with a great playground for DS, aged 2, and within walking distance of Crystal Palace, Dulwich and Brockwell Parks, plus Streatham Common. And we are within easy walking distance to Crystal Palace/Dulwich/Herne Hill. Plus the views are amazing.
It also has the excellent 'Feast' food/craft fair every month, plus two fishmongers, a nice deli, a great bakery, 2 good coffee shops, and 3 small supermarkets. There are a few nice pubs too, though more in surrounding areas than in W Norwood itself. And W Norwood cemetery is lovely. Plus at the Gipsy Hill end the primary schools are great.
Sure there are parts that are a bit dodgy, and it doesn't have the most attractive high street in the world, but I have never ever felt scared walking home alone late at night here, and I can't say the same for when I lived in Chiswick or Balham!