Depends upon your age and if your riding will be mostly on widetrack and flowing singletrack or on singletrack with drops, switchbacks, and tight quarters.

Think of the 29er as a luxury car and the 26er as a sports car. The young person likes a very responsive car. The mature person likes a more comfortable car. The 29er will 'flow' and it will 'roll', but you cannot toss it around like a 26er. And, you are more likely to go over the bars on a 26er than a 29er; although it can be done easily enough on a 29er.

For rough terrain, the 26er can make good use of both front and rear suspension. The 29er is commonly a hardtail. For a new bike, the hardtail 29er is likely to be less costly than a FS 26er.

The gear ratio on a entry level 29er is often about 10 percent higher than on a 26er because the manufactures are using the 26er chainrings and cassettes (22-32-44 front and 11-34t rear) on the entry level 29ers in spite of the larger wheels .

Only you can answer your question. But, many riders have switched from a 26er to a 29er and far more of them seem to be happy with the switch than unhappy with the switch. In addition, the industry is moving to the 29er and the bike shops are promoting the 29ers. That means that the used market may see an influx of 26ers with corresponding price drops.

Take your pick; nimble and agile or smooth and graceful.