France is a fairly large country with a variety of different scenery. From the Alps to the Pyrenees to the rolling countryside of the north to the beaches of the French Riviera, if you want it, you've pretty much got it in France.
France has some of the most famous monuments in the world, even if they're not necessarily the most spectacular. The world-famous Louvre museum is certainly unique in style, but does not compare in content to, for example, the British Museum in London. The Eiffel Tower is impressive and offers a great view of Paris, but it's one of those "been there, done that" sort of things. The cathedrals such as Notre Dame in Paris are spectacular, but if you're addicted to cathedrals, Italy is a better bet. To wit, France has a great deal to offer in the variety and grandeur of its monuments, but it has very little which I would say "can't be beat."
Cold in winter and hot in summer, France has a fairly moderate climate. Spanning a fair degree of latitude, France's climate changes considerably from the far north to the far south, with the north being considerably more cold and wet.
France is generally held to be an expensive country, but it really doesn't have to be. If you eat like the French, you can eat affordably. If you drink like the French (wine, not beer), you can have some fabulous wines, dirt cheap. Accommodation can be expensive for one, but since most hotels in France charge the same for one person in a double as they do for two in a double, it can actually be quite affordable for a couple. Campsites are plentiful and cheap. "Treating yourself" is what gets expensive in France. Going out for a meal can be quite expensive, as can typically "non-French" things like American candy bars. If you're good at budgeting and bargain shopping, there's no reason a trip to France has to be that expensive, but it certainly can be.
French cuisine isn't famous without cause. While there is certainly plenty of unspectacular, cheap food in France, any decent restaurant -- even the truckstops -- will serve a meal that will make your mouth water. Even if you're on a tight budget, it's worth going out for dinner at least once or twice, just for the experience. For the budget traveller, a baguette, some cheese, a few slices of sausage and some fresh vegetables can cost as little as $3US, and makes for a great, cheap meal.
The French have a reputation for being the rudest people on the planet, but so far I've spent a total of about a month there, and I do not understand how they got that reputation. The only thing I can think of is that most people come to France not even trying to speak any French, and the French are not impressed. In general I found French people to be very friendly and helpful, very polite, and as long as they could see that I was at least trying to speak French, they were willing to use whatever English they might know.
If it weren't for all the dogshit covering the streets in France, I would say it's a pretty clean place. I've stayed in a couple of pretty dingy places in France, but in general, accommodation is pretty well-kept. The French are, however, totally obsessive about their dogs, and are not very good about cleaning up after them.
You want it, you got it. Stay in the north, and you've got reasonably flat terrain. Southeast, and you've got the Alps, southwest are the Pyrenees. Vineyards, forests, you name it. They've got just about everything except desert.
Roads are generally good, but I hate their cycle paths. French cycle paths, like many others in Europe, tend to alternate between being part of the road and being separate from the road, and often alternate without warning. Sometimes they end in curbs, sometimes they just disappear. Personally, I prefer it when they just don't have a cycle path. You can ride on any French road except the Autoroutes. Inside the cities, many roads are made of cobblestones, which are hard on a bicycle, particularly a fully loaded touring bike.