i am looking for a good one to get for my b-day and it need live data....

 

Amazon, get any that provides real time data. Those will run around $100 or more.

Or...get the Hawkeye from AB, which is LR specific....$$$$$$$$.

 

I've got an Actron, they make a number of models, in that price range. Read the live data for coolant temp and it made a believer out of me - the engine temp guage was designed by a lad with stock in the head gasket factory.

 

The Elm5 is nice. I got it from Amazon for $35 shipped. Need a laptop for it though. The Launch has always interested me...Amazon.com: Launch CReader V scan tool/code reader (437001): Automotive
Good luck with your purchase.

 

I had a ScanGauge II, bought off Amazon for somewhere in the $150 range. It's small, and mounts nicely on top of the steering column. It also reads fault codes, can reset the CEL, performs fuel economy functions and most importantly, the backlight color is user configurable, so you can pretty accurately match the color and brightness of your instrument lights.

 

I bought mine off of e-bay, under $100.

 

I have a elm bluetooth reader, with free software on my android phone or my android tablet I can read codes, and get real time data. I just leave it plugged in to the car and link up when I want to see what's going on under the hood.

 

I use an OT2 unit, about $200. It need an iPhone/iPad/iTouch to read/reset codes. It can be wired to a laptop for more but the software included is not my type... I hear that there are many other free softwares thet work with the OT2. Check the website.
The OT2 unit helped me set up the electric fans for the radiator... Savannah is right, the temp gauge is nowhere near the actual engine temp that the OBD2 says, the ECT is around 120 Celsius before the gauge jumps from normal to high and still not in the red.
I'd like to try the ELM chip next.
SD