Good prime

I'm looking for a lens that would be nice for mostly indoors portrait and cat photos. At the moment I have the da18-55, da50-200 and da55-300mm. Requirements for my new lens would be: Nice image quality, good blurry background and not too pricey. I've looked at some lenses that could be the perfect lens for me, but as I'm not very good in lenses, it's still a mystery which one to buy. Anyway here is a list of some that might be good for my intended purpose and I'd like to hear some ideas, thoughts of these and some other lenses too:
Sigma 50/1.4 EX DG 429.00 €
Sigma AF 30/1.4EX DC HSM 439.00 €
Sigma AF 28/1.8EX 369.00 €
Pentax SMC DA 40/2.8 Ltd 439.00 €
Pentax SMC FA 50/1.4 499.00 €

Out of those you listed DA40 would be my pick.
I owned one for 2 years. I nly sold it after I bought 43ltd.
Extremely good lens and outstanding value. Don't be fooled. f2.8 is fast enough for 90 per cent of indoor situation and the lens is focusing supefast, and is practically as sharp in the corner as in center even wide open!

BR
Peter

50mm is a suitable length for what you want.

The Sigma 50/1.4 is apparently marvelous (and big and heavy), but you could get a Pentax 50mm much cheaper if you don't mind getting a used one. Consider Pentax-F and FA f1.7 and f1.4 for auto-focus, or Pentax-A f1.7 or f1.4 for manual-focus.

Dont discount the older manual focus Pentax M or A 50mm. They can be procured from ebay for anything between £35 and £75. My 55mm is an absolutely fantastic lens for portraits. I took a pic of my daughter (on my portfolio) wide open which, for me, gave a fantastic image ( a fraction soft in the face hich I was very pleased with . a few stops up and its razor sharp.

I reckon, for the money, they are very hard to beat. i certainly wouldnt be without one

I have both the DA 40 and the FA 50 and think both are great! the FA 50 I use a lot indoors in places like the British Museum here in London where (especially at this time of year) it is incredibly dark inside. The 1.4 aperture means a shallow DOF but enables a quicker shutter whilst not having to go mad on the ISO and get grainy pics. The DA 40 I love as a walkabout lens on holiday because it is tiny, light, focusses in an instant and has a 49mm filter thread (as does the 50) which means that filters (e.g. poliariser) are cheap too. I guess the prices you have in your original post are Finnish prices - both lenses can be had a bit cheaper here in the UK but whether that saving persists if ordering from Finland I am uncertain...

Regards

Mat

Thanks all for the tips I still need to think a bit for the right choice, but I'll probably go for the FA 50/1.4.

After a longish thinking process I decided not to get a 50mm lens. Instead I bought the Tamron 90mm sp Di macro lens, as I've been thinking about macro photography a long time.

Regards,
Tobio