If you are willing to navigate Taobao, there are quite a number of MSI 3060 Aero ITX from reputable stores, where I got mine at around market price.
Also, I have made a complication of all the ITX cards in the RTX 3000 & Radeon 6000 series for my own reference, but happy to share it! Hopefully I didn't miss out any.
As ITX cards are generally tougher to find, there exists an ITX tax on top of the high prices now, so good luck on landing one!
Edit (14 Jan 2022): Added in Powercolor RX 6500 XT
Edit (5 Jan 2022):
Added in new cards, with the recent annoucements at CES 2022. Will update with links to the official sites in the future.
Edit (2 Oct 2021):
Was looking through a couple of sites and came across a couple of cards that are exactly at 200mm, feature a dual fan set up and shorter than EVGA's 3060(Ti) XC, although not really small, mini ITX sized GPUs, it will offer some more options for cases like the Skyreach Mini 4, and Sumilo S04.
Edit (14 October 2021):
Radeon 6600 announced and released in the wild markets, added in some 6600 ITX options into the list.
MSI RTX 3060Ti / 3060 /
3050 Aero ITX
- Dimensions: 172x125x43mm
- Fan blade rises a few mm during high RPMs and might (will) impact case compatibility (Source: I have a 3060 Aero ITX).
- 3060ti seems to exist only on the website.
- Aero ITX design hasn't changed in a couple of generations, and it looks neutral enough.
- Edit (5 Jan 2022): Added in RTX 3050 variant
Asus RTX 3060 / 3050 Phoenix
- Dimensions: 177x128x51mm
- 2.5 slots, which is a shame, as a lot of small sandwich cases can usually only take 2 slots.
- Asus's Phoenix design hasn't changed in a couple of generations, and it looks neutral enough.
- Edit (5 Jan 2022): Added in RTX 3050 variant
Colourful iGame RTX 3060Ti / 3060 / 3050
- Dimensions: 182x130x42mm
- Best looking of all ITX cards so far, but at 182mm long, it will have fitment issues in some cases, with a backplate, white and silver aesthetics.
- Edit (5 Jan): Card is smaller than official specifications, as official specifications include the dimensions of the PCIe bracket. An user on bilibili measure the card to be approximately 167x100x27mm.
- Edit: Has a LED Strip on the top of the GPU, where the RTX wordings are.
- Colourful primarily targets the Asia market, so availability would be even worse if you aren't based there.
- Edit: Just released for sale, but users are complaining of fan noise, possibly due to a faulty fan? (Thanks to @tinyitx for pointing this out!)
- Edit (5 Jan 2022): Added in RTX 3060Ti & 3050 variant
Palit RTX 3060 / 3050 Storm X
- Dimensions: 170x125x39mm,
- No backplate, neutral aesthetics and has RGB.
- Edit (5 Jan 2022): Added in RTX 3050 variant
PNY RTX 3060 / 3050 XLR8 Gaming Single Fan
- Dimensions: 170x125x40mm
- No backplate, neutral aesthetics and has RGB.
- Edit (5 Jan 2022): Added in RTX 3050 variant
Gainward RTX 3060 / 3050 Pegasus
- Dimensions: 170x125x40mm
- Essentially the same as the PNY, just different branding for different markets (I think).
- Edit (5 Jan 2022): Added in RTX 3050 variant
Maxsun RTX 3060 Big Mac
- Dimensions: 183x122x41mm
- Funny name and plain looking aside, the only dual fan ITX(?) card at 183mm, will have issues with some cases, and with a backplate.
- Maxsun's target market seems to be only Asia as well, availability will be an added issue.
Galax RTX 3060 / 3050 Metal Top
- Dimensions: 168x115x40mm
- Metal/silver aesthetics, has a backplate
- This specific Galax model is currently only sold in Asian markets, availability will be an added issue, but was showcased in Nvidia's worldwide 3050 annoucement picture.
- Edit (5 Jan 2022): Added in RTX 3060 and 3050 variant
Galax RTX 3050 1 Click OC
- Dimensions: 189x111x38mm (without PCIe bracket)
- Simple card, slightly long for a single fan card
- Edit (5 Jan 2022): Added in RTX 3050 variant
Asrock RX 6600 XT /
6600 / 6500 XT Challenger ITX
- Dimensions: 179x124x40mm
- Only Radeon offering so far, but unreleased.
- Has a metal backplate, no frill looks.
- Edit (14 October): Added in 6600 (non XT) Challenger ITX, ASRock's technical page on the card is likely an error, listing the card to be bigger than what it appears to be.
- Edit (5 Jan 2022): Added in RX 6500 XT variant
MSI RX 6500 XT Mech 2X
- Dimension: 172x110x42mm
- Dual fan, black and silver metallic looks, possibly has a backplate.
- Edit (5 Jan 2022): Added in RX 6500 XT
Powercolor RX 6500 XT
- Dimension: 165x125x40mm
- Single fan, black looks, no backplate.
- Edit (14 Jan 2022): Added in RX 6500 XT
Slightly too long "ITX" Cards:
ASUS RTX 3060Ti / 3060 / 3050 Dual Mini
- Dimensions: 200x123x38mm
- Dual fan, backplate, small RGB strip.
- Edit (5 Jan 2022): Added in RTX 3050 variant
ASUS RX 6500 XT Dual
- Dimensions: 200x123x38mm
- Should be the same dimensions as RTX Dual Mini options, official specifications/dimensions aren't out yet
- Dual fan, backplate, small RGB strip.
- Edit (5 Jan 2022): Added in RX 6500 XT variant
Powercolor RX 6600 XT /
6600 /
Fighter
- Dimensions: 200x111x39mm
- No backplate, no frill looks.
- Edit (14 October): Added in 6600 (non XT) Fighter
Sapphire Pulse RX 6600
- Dimension: 193x120.05x40.05mm
- Black and red metallic looks, has a backplate.
- Edit (14 October 2021): Added in Pulse 6600.
- Edit (5 Jan 2022): Added in RX 6500 XT variant
Gigabyte Eagle RX 6500 XT
- Dimension: 192x117x38mm
- Dual fan cooler, looks neutral
- Edit (10 Jan 2022): Added in RX 6500 XT variant
Bonus: If you have a 3060Ti dual fan card that has a short PCB and don't mind taking apart the card, you can consider doing Revoccase's
3060 Ti mod, making use of the Palit's StormX cooler.