A question right up my alley. I am fascinated by all of them, even lava fields (kipukas!) and deserts. But mostly, in general, I like what can be termed Transitional Biomes, especially between land and water. I miss living near big waters.

In my local area, my favorite is Granite Monadnocks. For example... [arabiaalliance.org]

Mediteranian-northern coastal California, coastal Oregon and coastal Washington state.

Subtropical mist forest interspersed with wet schlerophyll.
Everthing from dagger orchids in the remnant antarctic beech groves to sundews on the rhyolite clays.

I work in wet coastal, mainly swamp sclerophyll forests. though my faves would be coral reefs.
Reefs go without saying, awesome, colourful exciting.
Swamps less so, but I have a couple of rarities under my belt, Thersites mitchellae though I only found shells as they are nocturnal and aboreal. I restored a 7 acre damaged habitat for them from 2009-2013, I still oversee the site. Way back, 1974 found Dactylothele habros which is a peripatus that I nickname Socrates. I visited the site last year after an absence of 42 years but did not find any this time around.

I love the deep ravines in Kentucky. The rhodedendrun is so thick, not only does it block the sky but it holds in the humidity. The humidity is noticeabley thicker, thick being a very good description.. There is moss growing on everything, as rock surfaces are alway wet. The whole thing is different shades of green and dark brown, flowers are scarce. Salamanders, frogs, and centepedes rule the world.

Desert of the southwest, particularly the canyonland.
It's geography mostly. Life out there is chiefly hidden. But the omniscient crows will find you.

I'm currently living in an Arid biome (Tucson, AZ) and it's wonderful. Warm during the day and cool throughout the night. However, I can't deny how relaxing it is to hear the waves hit the coastline. Perhaps an Oceanside biome is the best.

I'm living in it on the Oregon coast! Usually not too cold, 80 degrees is considered hot, we do get sunshine sometimes despite what people think, I have the forest and the ocean!
Although, if I could snorkel every day somewhere warm the rest of my life, I'd probably be happy there too. As long as it didn't get hot...

I'm sorry this is off topic but this made me think of the movie Biodome. Also I don't think I could choose. I'm so fascinated by each one individually as well as how they can affect one another. For example, I watched something, I think it was planet earth, that said there's a desert near the ocean and for a long time they couldn't figure out why it wasn't lush like everything else around there, turns out the shape and height of the cliffs between the desert and the ocean created enough thermal heat waves that it always pushed any clouds away. I wish I could remember what desert or even what ocean it was, maybe the atakama desert?

The balance of nature fine-tuned over billions of years to fit in certain niches and the diversity and symbioses just blow me away. humans however just clear it away and never surprise me with there feeble attempts at controlling nature and causing even more problems in doing so. there was an old lady who swallowed a fly, I don't know why blah blah.........................................

Tidal pools

Got ourselves an ecologist?