I use Aspen Snake Bedding over a layer of paper towel. Price is $4 for a 1 quart bag, $7 for a 4 quart bag, $12 for an 8 quart bag or $35 for a 24 quart bag. Advantages for me are that it is safe for reptiles, absorbent, odourless, light coloured (easy to spot pests or where it needs to be cleaned), easy to spot-clean or do a full replacement, and it suits the rest of my enclosure decor. If my enclosure was a click-clack, however, I would just use paper towel.
Only con I can think of is that it's dearer than newspaper or paper towel.