Hey,
the Mid-2010 MacBooks only have SATA II with 3Gb/s. You need SATA III with 6Gb/s to get the full speed of a current SSD.
You won't recognize any difference if you can get a cheaper one that has not the fasted specs, because none of all available SATA III SSDs will reach it's speed limit on SATA II, they will only run at about half speed.
But since your Mac is pretty old and you probably might use the SSD later on a newer Computer in an USB 3.0 enclosure for example I would also recommend the Samsung EVO 850. The Samsung SSDs seem to be faster and more reliable than other ones.
I have a 830, 840 and 850 and never had any problems, while my first Crucial SSD died after a few days and the second one I bought a few years later died after about nine months.
Do you want to keep the optical drive and just replace the HDD? I am not sure about the Mid-2010, but it might be that you get only 1.5Gb/s on the port where the optical drive is connected. Is it a MacBook Pro or just a MacBook and what is the exact model number?
Edit:
You can see the SATA speed of each connector in the System Profiler.