There are a lot of good tyres out there that will fit your bike, they are called "Slicks" and compared to most MTB tyres they roll so much easier!

Some questions:

How heavy are you?
If you are really heavy, like I was, over 300 lbs, when I got back on the bike, then the 26" x 2" tyres will be a good choice, lots of tyre to suck up the bumps, little chance of getting a flat. If you are lighter then go with a skinnier tyre, 26" x 1 1/2" or even less.


My old MTB converted to a SS with Kojak Slicks on it.
I really like the Schwalbe Kojak slicks, they are very good, they stick really well on the road. They come in various sizes, but here is a link to them on Amazon in the 26x2.0 size

http://www.amazon.com/Schwalbe-Kojak-Tire-Wire-Black/dp/B001IB3DSQ

The 26x1.35 would be a better choice, IMHO, I run them on my single speed bike and love them!

I also really like the Continental Gator Skins, the 26 x 1 1/8" should do you.

Your bike has 26" x 1.95" tyres now, so maybe the 1 1/8" option is a bit small, really depends on how wide your rims are.

I think a trip to your local bike shop is in order, someone there should be able to help you, you will love how much faster your bike rolls on the pavement when you have the slicks.

Now a word of advice, if you are sticking to the pavement, then the slick is the best traction you can get, road tyres only have tread on them because people are stupid and think they need it, they do not. When you think of how little of your tyre is actually touching the pavement as your ride, maybe about the same as your thumb print, the more rubber that meets the road the better grip you have, if you take away some of that rubber and replace it with nothing, due to a cut tread in your tyre, you are giving away traction, grip, the ability to stop, yes, even in the rain, really, trust me on this. Cars need treaded tyres in the rain because they go so very fast, we don't on a bicycle.

If you are going to go on some trails still, then a true slick is not what you want. The Schwalbe Marathon is another very good tyre, but it has some tread on it, so it will roll nicely, but do OK on trails, not off-road, but dirt trails.

I would certainly recommend you change the tyres to something more suited to the road, and get in the habit of checking your tyre pressure weekly, or if you don't ride for a while before you head out, a low tyre is not safe, easier to get a puncture and more work to move, buy a good floor pump with a gauge on it.

best of luck, if you have any more questions, please ask!

Cheers!

When I first put slicks on my bike I weighed 280 lbs and put on 1.5 inche slicks. The "shock absorption" was fine and I now have 1300 miles on the bike. I would recommend them, in fact, my next set I will go down to 1.25" if I can find them. My only issue is that I have had many flats - I have been using Kenda Kwest tires. The flats have been due to glass and thorns, but no pinch flats at all. I think that I will move to a "puncture proof" tire like the specialized armadillo next time around. I love the slicks. However I have recently picked up a second hand road bike and ride that A LOT as well. Good luck with your choice. Personally, I would go as narrow as possible. If you have a shock up front then you don't really need a wider tire for comfort on the bumps. That is my humble but esperience based opinion.