The Knockout series:
Most people are familiar with this series, it's the number one asked for rose in garden centers with good reason. While no rose is completely disease free, it's hard to beat the disease resistance of the Knockouts. With the exception of Rainbow Knockout, they are also self-cleaning which means you don't need to dead-head. I still dead-head them anyway, since this will increase the amount of rebloom. They are not all that super-hardy though, and require some winter protection in zone 4, and it's not a bad idea to give some protection in zone 5 as well. Protecting them is relatively easy, I just mound 8-10" of mulch over the crown of the plant once the soil freezes for winter. This is usually enough to get them through the winter. Once the ground thaws, pull away the mulch and cut off any canes that have died over winter.
The Easy Elegance Series is much like the Knockout series, but there is far more variety in flower color, flower form, and fragrance. Hardiness varies by variety, but I have grown a number of them without winter protection. If in doubt, winter mulch as for Knockout. Disease resistance on almost all varieties is excellent. Some of my favorites include All the Rage, Grandma's Blessing, Macy's Pride, Kashmir, My Girl, Snowdrift, Sweet Fragrance, and Yellow Brick Road. Having said that, I don't dislike any of the varieties in the series.
Home Run is a great single red rose from Weeks Roses that has excellent disease resistance. The foliage always looks great. It is self cleaning, but just like Knockout I dead-head anyway. Winter hardiness is about the same as Knockout. Winter mulching is neccessary in zone 4, and not a bad idea in zone 5. There is a hot pink version coming in 2011 called Pink Home Run which looks promising. A better name would have been nice, maybe Grand Slam to continue the theme?Midnight Blue and Rhapsody in Blue are both great dark purple roses from Weeks Roses that have proven to be fairly hardy and disease resistant for me. I didn't do any winter protection this past winter and both came through beautifully, only to be trampled by the dogs. Dead-heading is recommended for re-bloom.
Champlain is a great hardy red that is fairly disease resistant. I haven't had to spray mine yet,
but they do get a little mildew and blackspot. You have to look pretty hard to find it though.
Champlain is a larger variety, growing 4-5'. I don't do any winter protection, and get very little
dieback. This is a profuse early bloomer, and the first bloom for me lasts almost through July. You can dead-head to keep it looking it's cleanest, but I wait until it's done blooming and cut it back 12-18" to remove all of the flowering stems. More flowers follow in August. This is a fantastic, easy, variety. Great for anyone who hasn't grown roses before.
Hope For Humanity is another very hardy red that has done well for us. It is less disease resistant than the others, and may require spraying in a hot and humid summer. This one is hardy to zone 3.
Heart and Soul is a fairly hardy variety with beautiful rose and white bicolored blooms. Winter mulch is a good idea in zone 4, but probably not neccessary in zone 5. This one may require spraying as well, but blackspot and mildew haven't been too bad on it.
Watercolors is a single rose from Weeks Roses that is a little hard to describe. It starts out a blend of pink, yellow, and cream and changes to solid pink as the flowers age. Disease resistance has been very good, as has it's hardiness. 
Winnipeg Parks is a great hardy magenta with large flowers that is very hardy and fairly disease resitant. This one overwinters in zone 4 without any problem. Another great one for beginning rose growers. Carefree Spirit is a great red single that has shown excellent disease resistance and good hardiness. No winter mulch needed. I really like this one.
The Oso Easy series from Proven Winners shows a lot of promise. Paprika is my favorite, as it has the most unique color of the series so far. Cherry Pie is another red single. So far I like Carefree Spirit better. Strawberry Crush is an interesting rose-pink color, and Peachy Cream is a peach that fades to cream as the flower ages. Fragrant Spreader is a groundcover rose with small single pink flowers that are supposedly fragrant. I honestly haven't noticed. This one seems to take a long time to rebloom, and I'm not real impressed with it so far. They all seem very hardy so far, and show good disease resistance. They are self-cleaning, which is great since they are a dead-heading nightmare! They are incredibly profuse bloomers, and trying to deadhead is almost a losing battle. I may try shearing them back in the future.
There is vast number of other hardy shrub roses that will do well all the way to zone 3, these are just some of the newest or my favorites. Don't be afraid to grow roses, there's a rose for nearly every gardener.
