The accucheck one is by far the best imo. It is far far less fiddly to change the lancet than others, and there is no risk of you impaling your finger inadvertently, and the lancets come in drums of 6 so you have to change them 6x less, and you never have to see the horrible scary needle (seriously the last point is very important for me! Lancet needles are worse than the insulin needles, I think because they are/look thicker).
If you and 3 others can't get it to work, I'd assume it is broken. But just case it is not, do you have the instructions, and a new lancet drum?
To get it to work (if it is not broken) if you don't have the instructions: take the cap off. Take the drum out (you should see red marks on it. This is to show it is used). Get a new drum (if you can see red marks on it, it won't work). Insert drum into device, blue end first. Press it all the way in. Replace cap. Set depth setting to 1. Click end in (the opposite end to the drum). The button near the cap should go yellow. Hold device at side of fingertip (I'd suggest you try, assuming you don't have nerve damage to fingers?). Press yellow button. If you can't feel anything, try again with depth set to 2 - swivel end round to change lancet (in the direction of arrow) and then press end in and hold against fingertip and press button. If that doesn't work, I'd assume it's broken.