For around town I wear jeans. No special reinforcement, just plain everyday jeans. If it's cold/wet I wear a pair of pull on Spidi pants over the top of the jeans. For days when I go for a ride through the nearby hills I wear these
www.tigerangel.com/toursp_mens.html (I don't know if they're available in the US, it's an Australian company). Their main office is not too far from where I live so when I bought the pants I had them alter the Dainese leather jacket I already owned to zip together with their pants and they did it at no extra charge. I had to come back a couple of days later to pick up they jacket, it wasn't a same day alteration. I bought the pants 5 or 6 years ago and I've never had a problem with them. I wouldn't hesitate to buy their stuff again if I needed to.
I always wear decent boots, jacket, helmet and gloves. I never ride in shorts, sneakers, just a t-shirt or without gloves. I don't care how hot the weather is or how short the ride is, if I'm on a public road with other traffic I
always have full skin coverage. A little bit of discomfort is vastly preferred over surgical skin grafts. I realise ordinary jeans don't offer a lot of protection, but it's better than no protection at all.
Edit: Tiger Angel will ship internationally, but I don't know what the shipping price will be and you won't be able to try their stuff on first.