Well, it's only fair.

Chandra's Phoenix is a classic. I honestly don't know what I'm looking at to this day.

Ixalan's owl faced phoenixes win for creativity points.

Shivan Phoenix

Bogardan Phoenix

Molten Firebird

These are the phoenix arts that really stand out from a lot of undifferentiated ‘fire effect with a beak’ artwork.

I do like dragon but I do wish we got a few more places without them and let Phoenixes shine. I adore the owl looking ones in Ixalan.

I do like how each phoenix has a different way to return, it gives them all a bit of creativity and I think works really well with set mechanics a lot, as such tying it to landfall or cycle.

I mean, I do understand coming up with new mechanics for their ressurection has to be taxing, but I very much would like a world where phoenixes are in all five colors. Like Tarkir, except less stupid.

As someone who likes birds and also likes fire, it's not really a surprise that I enjoy a lot of phoenix art. Standouts for me include...

Aurora Phoenix for mixing in some contrasting colors.
Kuldotha Phoenix for pulling off a super dramatic take where everything behind the front silhouette is just an unbound trail of fire.
Molten Firebird for going darker, focusing more on lava and smoke over bright fire.
Rekindling Phoenix for being a cool owl with incredible contrast. Even the framing is beautiful with the reflection in the water, the glowing trees, and the city for lore context.
Shard Phoenix for looking cool despite having no fire at all.
Warcry Phoenix for another ominous high-contrast take that also gives us a sense of action as we see it hunting some prey.

I think, art wise, my favorite phoenix is magma phoenix because that is some dynamic highly frenetic art. Ironically, it earns this top spot not on its own merit though. There was a game of Duels of the planeswalkers ( plane chase version) where I drew into the phoenix in the onakke catacombs and it looked AWESOME in black. It was also a serious threat.

Similarly, I find phoenix of ash for it's awesome undead appearance. Though I wish it actually was also a skeleton or something.

I also think it would be cool to explore alternate takes off what qualifies as a phoenix, like with lightning phoenix

On the flip side, I seriously hate, and always have hated, worldheart phoenix. I hate the card mechanically, but more, that art is just trash.

Things like lightning phoenix and arclight phoenix kind of makes me curious how Creative would handle thunderbirds in a hypothetical indigenous american setting.

I'd be fine with things like storming entity getting an errata into a phoenix.
Essentially, if it's an elemental bird, I think it could qualify.

Can't be any worse than what they've done with hydra.

I think they would be separate things since thunderbirds have their own myth and stories. A quick looks, it also seems like thunder birds don't die and re-birth which I think is a pretty key flavor factor imo of a phoenix-phoenix like beings.

To be fair the phoenixes in the Plane of Mountains and Seas also don't get back from the graveyard, which shows how Creative is willing to bend for specific mythological needs.

Thats based on the Fenghuang or "Chinese phoenix" thought really they imo should be separated but magic isn't the only thing to call them phoenixes, see the remake of Mulan (or don't it bad).

Yeah I know. The Chinese "dragon", "phoenix" and "unicorn" have nothing to do with dragons, phoenixes or unicorns, though at least the latter have the type Kirin.

I absolutely adore Rekindling Phoenix. It's my favorite magic phoenix art by a mile.

I also like Skyfire Phoenix.