What website or tax return agency will give me more benefits on my tax return?

Unless someone screws up, anyone will come up with the same refund

You want accuracy, not more refund than you qualify for. Beware, there are fraudsters out there who will promise you the biggest refund. Find a competent and ethical tax preparer and you will get the best refund legally possible.

They should all give you the same, if they do everything correctly.

If one of them seems to be giving you more, then do not use that one. If the amount that you think you get is more, that means that they are doing something very wrong, and you won't get to keep the money, so you'll actually have less (or nothing) in the end, because when the government discovers what they did wrong, you are required to pay the penalty out of your own money, even if it's the website's fault.

Assuming the same info is entered, everyone should give you the same answer.

Ironically, any place that promises you more should be avoided.

They'll all end up about the same, unless someone does something illegal or screws up. If you have little other than a W-2, the law leaves almost no room for tax minimization and planning.

If you have a small business or a complex tax situation, though, you need an enrolled agent or CPA. The people who do the grunt work at chain tax prep companies like Liberty Tax, H&R Block, etc. don't know their anus from a hole in the ground when it comes to tax law and are very likely to screw things up. At the end of the day YOU are responsible for your tax return, not them. Saying, "but I hired Slick Willy's Tax Service to do this for me" won't get you out of having to pay what you owe.

They should ALL be the same, as they are and their programs are set up to meet tax law/code.

None. Same info entered, same refund from anywhere.