I live in the north end of Palm Beach Gardens off of Donald Ross: most people assume my neighborhood is in Jupiter, so I can speak as a 'near resident' of Jupiter. I do most of my shopping in Jupiter, most of my diving with Jupiter Dive Center and go to Jupiter Beach when my wife and I want to walk the dog on the sand. There are a lot of pleasant parks in Jupiter (e.g. River Bend park) and some arts activities (Maltz theater).
I have no idea of the crime stats, but this feels like a very safe place to live. I've been here a little over 5 years and have never had any issues that you might not experience anywhere else in the country.
It is hard to give advice on where exactly to live since home price ranges are extreme in Jupiter. Admiral's Cove, a gated community, has many $1+ million homes. Abacoa has many homes in the $300K range and probably less for some of the condos, there are a few areas like Jupiter Farms that are not gated and a little more 'wild west' like where homes can range from the mid-150's up to $700K or $800K and houses are on 1+ acre lots but there are no Home Owners Association enforcing any sort of standards. By the way, I don't mean to be duragatory when I say 'wild west': I live in a neighborhood that is very similar to Jupiter Farms, so have personally made the choice to avoid a gated community.
If you don't mind driving to work or diving, you can find some great deals on homes and condos in the Port St. Lucie area. There are also some really nice but not terribly expensive neighborhoods in Stuart but the commute can be a haul if you are far from I-95.
Palm Beach Gardens (PGA Blvd) also has a range of home prices, but probably has more opportunity for less expensive homes and condos.
In both PBG and Jupiter, note that the age of the population increases dramatically in the winter with snow birds. Most tend to be from NY or New England. Depending on the vibe you like, that could be a good thing or bad thing. Anyway, the restaurants are more crowded during the winter, but slack off in the summer.
I completely enjoy living here after having spent time in Chicago, Detroit, Columbus Oh, Philadelphia and southern California.