There are many dozen different types of blueberry varieties to choose from, and figuring out which is the best for your particular circumstances can mean a little research before you buy plants.
You can class blueberries into a few general categories to help you decide. Firstly, there are some that need more cold weather in the winter than others. These are usually classed as either Northern or Southern varieties though other terms are sometimes used. Northern blueberries can handle colder climates and they also need more cold to develop fruit properly in the spring. Southern berries prefer things to be a little warmer overall.
The other broad category would be Dwarf, specifically for the smaller plants. Of course, dwarf plants can be either Northern or Southern as well.
Within each group, you can see which types produce the most and how long they will take to reach maturity. Some varieties are wide-spread and some may be unique to your local nursery. Details on the specific varieties here have come from multiple sources   
Patriot: This is good hardy variety that will produce large berries early in the season. It's known to produce a high volume of berries and the bushes tend to still stay about mid-sized.
Chandler: You will always get very large berries from a Chandler plant, which is ideal if you prefer to eat them fresh and whole. They will ripen later in the season, and usually over a period of several weeks, so plan on doing more than one round of picking. You will get a huge harvest from these plants.
Bluecrop: This variety also comes in mid-season and does have large berries as well (not quite as big as the Chandler berries though). Bluecrop is a very common variety across the country for its good yield and reliable growth. The berries are a little more tart than some others, and lighter in color.
Toro: Toro berries are quite similar to Patriots, though they usually come into season more in the middle of the season rather than early.
Bluejay: These berry plants are often chosen for any situation where you are going to pick with a machine. They usually ripen all at once for a single harvesting session and the berries are very loose on the plant. You will be able to harvest these a little sooner than mid-season.
Earliblue: And as the name suggest, this is the earliest producing variety you can get. You can get a jump-start on the season (usually around June or earlier, depending on your climate) though these plants will produce smaller berries and are not as cold-tolerant. You'll only be able to plant them in Zone 5 or higher.
Breeders and botanists have developed many blueberry types that can thrive in warmer weather without the heavy chill of winter. These are more likely to be unique to each nursery because they a relatively new phenomenon. If you can't find these specific types, see what your local nursery offers.
Biloxi: This berry will start to produce around the middle of the season and requires a minimal amount of chill weather in the winter. It's a very good blueberry for warmer climates. The fruit is average-sized but the bushes can get quite large so you will likely have to keep up with the pruning.
Sharpblue: Sharpblue is similar to Biloxi in berry size and a preference for warmer weather. The bushes will also grow large, but this variety will start to produce a little later in the year.
Oneal: You will get larger berries with Oneal, and these bushes will produce earlier as well. For a Southern berry, they do need colder temperatures in the winter to develop properly so these berries are not as well suited for the far-south areas (no higher than zone 7 or 8).
Springhigh: If you are looking for an early bearer, see if you can find Springhigh plants. These are very early and will start having ripe berries in the spring rather than the typical summer harvest. Not only do they ripen early, you will be very large berries from a Springhigh.
Tophat: These are the best known dwarf blueberries, and the ones you will most likely find at the nursery. It is very popular for small yards or even container gardening as the bushes usually don't grow much taller than 2 feet high. Their berries are average-sized, and they are usually ripe a little later than mid-season. Tophat berries are also not quite as sweet as the larger types.
Other types of dwarfed plants have been developed, but they are generally just short versions of the above mentioned plants and they can vary from nursery to nursery.
Another factor you need to consider is pollination when buying your plants. Some plants require others of the same type within a few feet in order to pollinate properly and to set fruit. If you are already intending to plant several, then it isn't going to be a problem as long as you plant them near one another. But if you are really only looking for 1 or 2 plants, you need to get those that are referred to as “self-fertile”. More information on this is on the pollination page.