If you are trying to conceive or in early pregnancy, this is the default the evidence actually supports. Plain synthetic folic acid is the form used in the landmark MRC and Hungarian trials that established folate's protection against neural-tube defects (NTDs) — no methylfolate product has ever matched that trial record. Nature Made delivers 400 mcg of folic acid (665 mcg DFE) in a USP Verified tablet, meaning an independent body has confirmed the label.
At roughly $11 for 250 tablets it costs a few cents per day. This is the boring, correct answer, and it earns the top spot precisely because it does not chase the methylfolate marketing story.