Not an REI employee but I few I would consider are the Thermarest X-light Large and the
Nemo Tensor large wide (out of stock) and the Sea to Summit ether light-XT Large Mummy. 

Personally not a fan for REI's house pads but that's just me.  They have been a bit variable over the years and tend to change designs a bit too often to be sure of them.  ymmv.

Therm-a-rest Neoair XLite Sleeping Pad  Large is 77 inches long and 25 inches wide at shoulders and 2.5 inches thick.  I'm 6ft and around 195lb and use a regular size although I would recommend a regular wide (25inches)  for back or mobile sleepers of my size.  This is probably the most popular pad with through hikers.  It is a bit crinkly noisy if you move around a lot which bothers some.  With an R value of 4.2 it is a much better insulating pad than any closed cell foam the best of which are around 2.    Treated with care these are robust and not prone to popping or deflating.   That said the included repair kit is effective.  I lent mine to someone and they manage to puncture it with a fitting on their katabatic quilt somehow (little knife shaped things...go figure) but the field repair was quick and effective, lasted the rest of the JMT and I'm using the same pad this year with no problem.

Nemo Tensor Air Pad  Large wide is 76X25X3 but that size seems to be out of stock at REI and Nemo currently.  It is a well regarded comfortable pad but heavier than the X-lite.  I have no personal experience.  There is an insulated version that has a higher R value. 3.5 vs 1.6.  I would get the insulated.

Sea to Summit Ether Light XT Insulated Air Sleeping Pad  Large Mummy is 78x25x4  R value 3.2  It is a thicker pad than the xlite or the tensor.  Have heard good things but I have no personal experience.