So, you know what didn't work for me.  So what do I like?

I like stuff that truly makes things easier or faster than I used to.  Also, I like things that allow me to do procedures that I couldn't do before.

• Easier/faster: 
  
• digital x-rays:  I use Sigma Biomedics intraoral sensors.  There a relative unknown but I've found their prices to be good and they're receptive to problems.  We've actually had a sensor or two with troubles and they're replaced them without the ridiculous maintenance schedules of most digital x-ray purveyors. 
  
• rotary endo: I say this with a note of caution because doing endo well has everything to do with attention to detail and very little to do with what file you use.  Using rotary endo doesn't mean you can throw out the principles of endo.  Rotary endo doesn't allow you to do molar endo in 30 minutes.  Endo can't be rushed.  You're trying to remove living and dead tissue while also removing microscopic bugs, not putting a white stripe down the tooth.  Rotary endo increases efficiency, but isn't a magic wand.
• digital cameras:  This falls under the "new procedures" heading, too.  I didn't use to take photos because the development/knowledge gap was impractical for me.  I've been using a Canon 10D with a macro lens and ring flash for some years and it's made a difference for me.  It's point and shoot, even though it looks really intimidating.  I recently added usb intraoral cameras to each operatory.  After years of dogging intraoral cameras I finally started using them.  It's a great thing to have available.  The photos aren't as good as a digital SLR, but they're much easier for "show and tell" in an exam.  Worth every penny IMO
• networked computers with practice management software in each operatory:  This is where technology starts in my opinion.  If you can't access your information throughout the office you're missing out on the advantage of having a computerized office.
• Procedures you couldn't do otherwise:
• digital pano: We added this recently.  This is probably the greatest ROI I've had in dentistry.  I'm seeing better stuff, explaining conditions to patients better and charging for a pano (which I haven't ever had before).  Probably the best technology decision I've ever made.  If you're on the fence about a digital pan my only advice is DO IT!
• digital cameras/USB intraoral cameras: I don't charge for the photos I take, but being able to show the patient their teeth up close in real time has been very valuable for treatment planning.  It isn't hard for a patient to see a failing restoration when it's well lighted and as big as their head on a monitor right in front of their face!

There's a lot of other "new procedure" type technology out there that I haven't experienced.  One appointment crowns and onlays with a CEREC is a very popular one and "new attachment" perio procedures with a laser are too.  The only concern that I have about them is that once you have this new hammer everything starts looking like a nail.  Base your purchases on sound science and realistic procedures and you'll do O.K.