The Samsung F490 is
£389.99 and the SE K850i is
£249.99.
If I had the choice, I usually go for the most expensive.
Keep changing my mind what I would go for. I've never had a touchscreen so maybe I'd go for the Samsung. I also like the Samsung brand more then any other. My past two phones have been Sony Ericsson but I don't think my next will be. They haven't been great for me. I say get the Samsung F490, but you're choice.
As for the Nokia N95, I thought it was good by what I'd heard, but reviews say differently. Up to you if you like it or not.