Google Forms

Google Forms answers one question completely and most others plainly: it is free, with a Google account and no cap on responses.

The ease of building follows from how little there is to learn. Questions are added in a list, sections can branch on an answer, and the form is shareable in minutes; value for money needs no argument at all, because there is no bill. Responses can be written straight into a Google Sheet, where they behave like any other data. Customisation is the sharpest limit of all. Appearance stops at a theme, so the form always reads as a Google form rather than as part of the site it sits on.

The cost is what happens after submit. There is no payment field and no calculation across answers, uploads require respondents to sign in to a Google account, and control over appearance stops at themes. A spreadsheet row is a fine destination, and it is where the native path stops — anything past it means wiring up somebody else's tool.