Some of the racing setups used on mountain bikes have 1.95 tire mounted on rims that would be the sort of widths used for 23 to 25 mm road tires if the same extrusion was used in a 700c rim. So you really want to check the rim itself. If it's one of the more narrow types you'll be fine with any of the smooth road tires in the 26 inch size.

Cruiser tires are 26 but they are the "other" 26inch size. The one that uses a different size of rim.

Fat tires like the Big Apple and Kenda K-Rad are fine if you want to do city trials or city jump riding. But for use on a bike that you want to be fast and sporty they fail big time. I put a set of 2.35 K-Rads on a bike and it made it feel so much like I was riding through draggy sand all the time that I was going to sell the bike. I then put some Tioga City Slicer 1.25 width tires on the same bike with no other changes. It was like someone had put a big Hemi engine into the bike. It felt totally lighter and quicker. It was this bike that proved to me that 500 grms of weight on the rims and tires of rotating mass is easily more harmful than 5 kg's of static weight on the frame or in a backpack. So if the idea is to have a fast and sporty city ride then stay light and stay narrow for the tires.

Options that I have personally tried and would suggest without any reservations are Panaracer Pasela 26x1.25, Tioga City Slicker 26x1.25 and Ritchey Tom Slick 26x1.4. The Pasela ends up being the narrowest and most "road bike" like but the Tioga and Ritchey both roll almost as nice and offer a shade more tire section to withstand bumps and bangs.