I've been using the winter tyres for many years now!
To start with I would NOT recommend using 195/50/15 for Winter Tyres, the profile is too low! I personally use 195/50R15 in the Summer and 185/60R14 in the winter - narrow tyre with bigger profile would give you better traction in snow and in wet, not to mention that 14 inch tyres are cheaper then 15 inch -) The bigger the profile the better the tyre for snow/wet traction.
I personally use TOYO Snowproxes S942
http://www.toyo.co.uk/tire/pattern/snowprox-s942
http://www.tyretest.com/cgi-bin/autotest.pl?104z117z111
The review based on 109 feedback is very good, with average 4 out of 5 stars, with most people advising that they will buy this tyre again! And I will buy them again as well -) These tyres are just awesome, no matter the weather, dry\wet\snow\ice!!!
The tyre is not directional so I can swap them regularly for even wear.
Don't listen to ALL season marketing bullshit - like Adam said you always sacrifice something. Get proper snow tyres which will help you to get a grip in snow/ice as well as improve your driving experience in heavy rain of flood.
I put snow tyres in December and keep them on till March every year and even though a lot of people call me pussy for doing that, I don't care, if it snows I can drive anywhere anytime uphill or down the hill, not to mention that my braking distance in wet is pretty much the same as in dry!!! One thing to remember though that don't keep the tyres older than 5 years as even if you have plenty of thread left on it, they won't grip well. I've learned the hard way - when I bought the car my rear tyres were Falken M+S with a lot of thread left on it, but it didn't grip well on the corners, it turned out that my tyres were 9 year old -))))
Remember when buying a tyre to look for a SNOW FLAKE sign on the tyre, not just M+S (Mud and Snow), like this one
"In 1999, the RMA (USA Rubber Manufacturers Association ) defined a real “snow” or winter tyre with its severe snow-rating. Car and AWD tyres that pass this performance test and are embossed with the “snowflake on a mountain peak” icon. Severe snow-rated tyres must provide traction at least 10% better than a standard reference test tyre.
The off-road, all-terrain and all-season M+S tyres cannot pass this test. The M+S rating doesn't mean much. The severe snow rating does."
Other popular brand for winter tyres would be Nokian, Bridgestone, Falken and of course Michelin.