I arrived about Jan 3 and returned Jan 10. First trip to Bonaire. Here are a few thoughts. If you have any questions, reply here or PM me. I'll be glad to add to this.
Diving: Of course, the big draw is the fact that so many fish (and other things) can be found in such clear waters, just off the beach. The entries were not quite as easy as I had imagined however. Most of the beaches I visited were several inches deep in broken bleached thick coral fragments, and at some sites, there was a hard ledge (I assume of ancient coral) at the waters edge. The beach coral chewed the hell out of my fins, and the slippery ledge which extended into the water (I'm thinking mostly about sites south of the city) made it difficult to get a firm footing. I actually got knocked down by some very mild waves on one exit and wallowed around in the "surf" like a drunken walrus for a minute or so, coming out with a few bruises and, as I discovered later that night at dinner, an urchin spine tip in my elbow. I was more thoughtful after that and didn't have any big problems on later dives but did have to be very conscious of my entries and exits.
My favorite dive sights were south of town (Angel City, Hilma Hooker, Invisibles). There were plenty of fish, the entries/exits were more manageable than some other areas (despite the fact that this was where I got knocked down), and access was good (i.e., lots of beach without buildings or parking lots). I was going to do a dive up in Washington-Slagbai Natl park, but the currents were a bit heavy that day, and since I wasn't sure how they moved in, out, and around the headlands of the coves, and since I was diving solo, I didn't do the dive...but it was very pretty. BTW, a trip through Slagbai should only be attempted with a jeep or PU truck. It is unpaved, rutted, VERY bumpy, and long. My scuba tank bounced off its rack in the back of the truck very early on.
By the way, my hotel had some sort of arrangement with Dive Friends of Bonaire where I got a 10% discount. They were OK, but I got a much better vibe from a place just a little south of town called Belmar Oceanfront Diving. I went in to get a replacement clip for a fin and ended up signing up with them to do a night dive. I did two night dives - one with Dive Friends of Bonaire that was just in front of their shop, and then the one with Belnar where we went south to the Salt Pier. Anyway, I really enjoyed the 2nd.
Crime: Yeah, its a problem. After reading some other posts about this, I e-mailed the place I was staying (Coco Palm) a few days before I arrived and they never returned my e-mail. When my rental truck was delivered, they asked if I wanted insurance. They explained the gas thieving problem. I declined the insurance, and sure enough, a couple of days before I left, my gas was siphoned out while my car was parked at night in front of the place I was staying (Luna Azul, I think was the name of the unit). The truck rental people actually warned me to not fill up so I wouldn't lose a whole tank (gas is like 3-4 times more expensive down there vs the States). Fortuneately, they just siphoned the gas. I had to pay $30 for someone to come out, check the truck out and put a couple of gallons in the tank (which was on top of the $30). Often, they cut the gas line, and then the charge is $90 plus gas (unless you have insurance). I asked someone who worked at Coco Palm if I should park somewhere else and he suggested around the corner, where one of the residents had some dogs that barked at strangers. The next day, I went to get my car and saw that someone else's car was on cinderblocks with all the wheels missing. I confirmed later in the day that it was indeed a case of thievery.
Food: Nothing exceptional. I frequented lots of mid-high end places and didn't have a bad meal, but didn't have anything too memorable either. I was told emphatically by one person (who worked at a dive shop) that the Yacht Club Restaurant was heads and tails above anything else and judging by the fact that I couldn't get a reservation for 4 days (after I had left), I suspect that he was telling the truth. It's not what it sounds like, but a small place with not many tables, run by two people. I did have one meal I could recommend from a Tapas type place on the waterfront (a bit towards the north of the main city dock area). It was called something like Guarniciro.. or something but don't quote me on that. Also, going just a bit north of town, just past a circle (roundabout) intersection, is a place on the right called Eli's Deli which had some very nice sandwiches. I didn't care for the burger I had on the first day, but could tell the place a good vibe (kind of a gourmet deli) and went back and was glad I did.
Other Stuff: As I say, Washington-Slingbai park was a long bouncy bouncy haul. If you have the time, you may want to visit. The coves were very nice, and I saw Iguanas up their, which I did not see elsewhere. If you are so inclined, there were some trails that might be interesting to hike, assuming you have a day to kill and just want to do something different. There is also some volcanic topography up there whereas most of the rest of the island is fairly flat. Given the state of my tires, I was worried for much of the trip that I might get a flat. I think you could actually see a lot of what their is to see if you just go as far as then entrance/visitors center.
One thing I would recommend for sure is the kayak mangrove trip run by the Mangrove Research Center (I think that's what its called). You will see flyers for this all over. Anyway, do the one with the snorkel component. And if you go at 8:30 like I did, you may have very pleasant weather. Its an education-oriented trip, but just a nice paddle also.
Well, I'm probably forgetting something, but those are the things that come to mind.
The Bonaire fanatics accept that as part of thier trip. 
You would be fooilsh to venture back there until the crime situation is cleared up, which does not appear to be any time soon.:depressed:
