There is no objective "best RPG of all time"—preferences vary wildly. Aveyond (2006–2010, Amaranth Games) is a beloved indie RPG series, but declaring it "the best" depends entirely on what you value.
Conclusion: Aveyond is an excellent indie RPG series with a devoted fanbase. It may be your favorite—and that's valid. But "best of all time" has no single answer.