Well, definitely if you've never heard Anathema you just have to do it. Immediately
Anathema (late Anathema as Mullholand had already said) is really emotional and just unforgottenably beautiful and just fucking great!

I can't express my feelings; maybe because it's too hard, maybe because my english is too mean
I would advise you to listen "One last goodbye", "Regret", "Deep", "Eternity part III (acoustic)", "Hope", "Emotional winter" to create something like first impression. That's exactly what Anathema was like a year, or two ago (their greatest period). They're moving forward now (as always) and of course you should listen to their last album.
Concerning first ones I wouldn't say that they're "bad" or... I like them. There you may find great songs for example "Sleepless", "J'ai Fait Une Promese", "Kingdom"... Style is similar to early November's Doom.
Anathema has been changing stuff badly during their way to the top

The greatest loss was, I think, Duncan Patterson who left the band for his new (great!) project Antimatter. He wrote a lot of material. He was a great member for the band. And after Dave Pybus left the band (bassist who replaced Patterson) Anathema hasn't a bassist yet.
Anathema also uses a lot of acoustic guitars (that's my weakness...) and if you liked Forever Autumn (sorry, Mullholand, I cannot force myself not to mention it again

you would like Anathema. Although styles are not very similar. Anathema does a lot of live acoustic show. To my great shame I haven't seen any...
Anathema is forever.