The best wax for wax melts is the one that performs well in the finished product and your warmer. Soy, paraffin, and blends can all be used successfully. The ingredient name alone cannot tell you how strong a melt will smell or how long you will enjoy it.
Wax is the base that holds the fragrance and releases it during warming. A maker also needs the finished melt to hold its shape, come out of its packaging, and tolerate ordinary handling. Different formulas balance those needs differently.
That is why a wax suitable for a candle in a jar is not automatically the right choice for a freestanding melt. The finished product needs to work in its intended format, not just have an appealing ingredient label.
Pay attention to how the melt performs in the warmer you actually use. Does it release a scent you enjoy? Does it remain pleasant over repeated sessions? Is it reasonably easy to portion and remove using your warmer's instructions? Those observations tell you more than a broad promise about one wax type.
If a plant-derived formula matters to you, check the maker's ingredient information rather than assuming a product is entirely plant-based from the word 'blend.' If fragrance performance is your priority, try a small amount before buying several packs.
A useful comparison keeps the portion, warmer, and room similar. Otherwise, a change in the setup can look like a difference caused by the wax.