whats the best reverb pedal

I like the flint because it has minimal functions and nails classic tones you hear on albums ranging from the 60' -80's. If you want weird or novelty reverb sounds go for the big sky, blue sky, or the new empress pedal. I usually stick with plate or hall sounds. The Flint has an amazing selection of trem's as well. Great buffer built in as well.
My favorite is the Mad Professor Silver Spring Reverb. It's simple, but is nice and does a nice clean spring reverb without the "flutter". I had a Hardwire Supernatural, and used it on the spring setting, but it had a pretty heavy simulated spring flutter that I didn't care for. The Mad Professor solved that problem for me.

It's also designed to sound good both in the loop and out front
Way too many available choices that are awesome but different flavors. I cant tell you what you like but neunaber are my fave reverb algorithms.
It's a little under the radar, but you may want to check out Gurus Sinosoid. It's actually a spring reverb built into a box, plus a 2nd channel of vibrato. Not as versatile as anything by Strymon or digital, but purely analog and actually the real thing, and it sounds terrific:

My favorite is the Matthews Astronomer so far. I sold my Empress Reverb once I got it. It sounded more warm, lush and natural in comparison. I find reverb pedals (or any modulation pedal) with lots of options tend to sound colder and less natural
Well for pedals, I haven't tried a lot (most of my reverb is rackmounted), but I do like the Eventide Space quite a bit. While there are a good number that I haven't tried, the ones I did try paled in comparison to a good rack unit. The Space came the closest. I've heard great things about Strymon and Neunaber.

For racks, I really like the Eventide units (H3000DSE, GTR4000, Eclipse) and the Lexicons (LXP15-II, PCM81, MPX1, PCM92). I've heard great things about Bricasti.
I am really diggin the DigiTech Supernatural Ambient Verb right now. All kinds of different flavors with this reverb, and much cheeper than some of the others. You can snag a used one for about 115, 120.
The best reverb pedal is relative to your needs.

Ask yourself some questions like:
What is my budget?
How much room do I have left on my pedalboard?
Do I want special reverb effects, like reverse and shimmer?
Do I need stereo I/O?

Depending on the answers to these questions:

My advice:
Eventide Space Reverb - Overal best with a big footprint
Digitech Polara - Best bang for the buck
Walrus audio descent - Best special reverb effects

If you'd like you can find out more about the best reverb pedals https://pedalrockstar.com/best-reverb-pedals/

Hope this helped out!
If you have the money then a Strymon Flint is a real good reverb with an awesome sound. You should definitely check them out if possible.
The thread is quite old, but hope my answer will be useful.

Recently I bought new reverb pedal EarthQuaker Devices Avalanche Run and I was very impressed by its sound. It makes deep and saturated ambient reverb and you can tune very long decay to it, even to loop it. Ideal for post-rock, shoegaze or dark ambient. Moreover, it makes also delay including reverse and swell modes, so you have a large customization options making your sound very interesting.

I would like to share the video of my band where we used this pedal. The quality of recording is far from the best, because it was filmed on smartphone:

Avalanche Run usage starts at 3.45:


By the way, you can listen to it in different modes here: