For many years the Rand McNally Road Atlas has been ubiquitous (sometimes under other titles). It is reasonably good, with clear highway maps, some features of interest, and is kept commendably up to date. But the topography is almost nonexistent and the maps are just not very attractive. Rand McNally also offers a reduced-size edition, the Compact Road Atlas and City Guide.
But now there is something similar but better, The National Geographic Road Atlas - Adventure Edition, produced in conjunction with MapQuest.
Why is it better? First of all, it is spiral bound, so it won't keep closing up on you, and the back cover flap folds in to keep your place. The maps are attractive, with clearly shown topography. It has an interesting series of climate maps, then a section with 36 scenic drives, from Alaska to Puerto Rico, each with a map and photograph. A gazetteer at the end lists all cities and towns, with population and map reference (though other map features such as mountains, parks, and lakes are not included). There is also a special RV and Camping Edition.
If your general-reference world atlas is more than a couple of years old, you need a new one! Teachers and geographers have always favored Goode's World Atlas, now in its 22nd edition. I have a whole series of them, going back to 1968 when I bought it for a class in economic geography at Berkeley. It has a well thought-out set of basic reference maps and a great number of thematic maps on world environment, resources, and human geography. This is the atlas universally recommended for college world geography classes and is appropriate for home schooling at the high school level. It is a reasonable size and a very reasonable price, even in hardcover.
If what you want is a large format traditional atlas I wish I could still recommend the Rand McNally International Atlas. Unfortunately it appears that they have abandoned the series and not revised it since 1994. But there is a worthy successor - the Great World Atlas from Dorling Kindersley (DK Publishing). It makes good use of satellite imagery and is very detailed and up to date. An excellent choice for a school or public library, or if you really love maps.
The Benchmark Atlas Series
My favorite atlases of western states are the ones by Benchmark - and not just because some of my former students helped produce them. They are a co-production by Allan Cartography of Medford, Oregon (who also make Raven Maps, see below) and Eureka Cartography of Berkeley, California.
The maps have beautifully rendered topography and meticulously researched cultural features such as roads. They show land ownership clearly (very important in many areas, especially the desert) and an intelligent selection of features of interest.
The scale is too small to use for hiking, but they are the all-around best maps to plan driving trips in the west. Most importantly, they will help you to understand the landscape around you as you travel. I always have one with me and consult it frequently on my long trips.
The Benchmark Road and Recreation Atlas series now covers eleven states, essentially the entire west from the Rockies to the Pacific coast. I would love to see them add Alaska, Hawaii, western Canada, and Baja California, but that seems unlikely. I also think California should be offered in two volumes at a larger scale (also not likely - DeLorme recently combined their two volumes into one).
All Benchmark Atlases highly recomended
De Lorme Atlases
De Lorme, based in Maine, has an atlas for every state. They are at a larger scale (i.e. features on the map are larger) than the Benchmark series, and they show tremendous detail.
The DeLorme atlases are excellent for back road exploring, they show everything that is on the large scale USGS topo maps. Early editions had crudely drawn contours, but now they feature shaded relief and accurate contours. The gazetteer is useful, listing all the place names on the maps, plus points of interest such as parks, boat ramps, and information centers.
The DeLorme maps don't show the attention to detail, field checking, and careful design of the Benchmark products. Nonetheless I have bought all of their western states editions and use them as a backup for the Benchmark Atlases. They are the only atlases available for some states.
Collections of USGS Topo Maps
The modern equivalent of an atlas is a collection of digital maps. The standard US Geologic Survey topographic maps (topos) are available on CD-ROM as the National Geographic USGS TOPO! series. You can browse them (as an interactive atlas) or define what you need and print your own hardcopy maps.
The interface is a bit unpolished but what you actually have is a seamless map at multiple scales. Zoom in and out, scroll around, then capture the area of interest to a jpeg file. You can also make notations, measurements and create elevation profiles. The main drawback is the price - $89.99 per state.