Pavers vs concrete walkway
Pavers:
* Reasonable to do yourself.
* Probably lower cost.  (2" of concrete, instead of 4"
* No cracking issues.
* Look cool (My opinion)
* If you are creative you can make interesting patterns.  Most come in at least pinky-red, charcoal, and natural.  Sometimes you can get white.

Pavers with a lock patter (zig-zag) and spacer nubs to leave a consistent crack are easier to work with.  But the wider crack (3/32 to 1/8) gives more opportunity for weeds to get established.

Pavers downsides:
* Weeds will grow in the cracks.  A flame weeder is quick to use when weeds are small.
* Pavers are a nuisance to shovel snow off of.  The edges aren't perfect, and can catch the edge or corner of a shovel.

Concrete:
* Quick.  2-3 days of inconvenience and they are done.  Pavers can be pretty fast to if done by pros, but not as fast as concrete.

Other options:

Breezeblocks.

I ran into these in college.  Make great bookshelf supports.  Reasonable way to get privacy inexpensively.  But the blocks can also be laid horizontally, and the spaces filled with grass, or other ground cover.  This leaves the surface quite permeable to rain.  Recommended if you want part of the lawn available for parking an RV.  The grass will wear where it gets driven on regularly.

Patio pavers.  

Pavers writ large.  Usually 24x24 or 24x30.  These have to have a VERY solidly packed base if you are going to drive on them, as they are usually only 1.5" thick.  There was a fad in California some decades ago to put in 2 strips of patio pavers to the garage, and to use pavers for walkways.  They come in various patterns and colours.  

Road crush:  This is what your local county puts on the gravel roads.  It's quick, cheap, and if you put edges on it can look neat.  If the crush is limestone or sandstone based you can 'fix' it in place with dilute muriatic acid.  This dissolves the calcium carbonate, which when the solution dried out, cements the rocks together.  You can also white wash the rocks.  It doesn't last very long, but whitewash is cheap.