I'm currently using A SanDisk Ultra card but have also been very happy with Samsung Evo Select Whichever is cheaper ATM is my recommendation. Both are incredibly reliable, but write speeds can be a bit quicker on the Samsung cards. But not impactful or noticeable in any case other than copying files on PC(not Vita Shell).
SanDisk Ultra 256gb https://www.amazon.com/SanDisk-256GB-MicroSDXC-Memory-Adapter/dp/B08GY8NHF2/ref=mp_s_a_1_4?dchild=1&keywords=256gb+micro+sd+card&qid=1630383695&sr=8-4 Samsung Evo Select 256gb https://www.amazon.com/Samsung-Electronics-microSDXC-Adapter-MB-ME256HA/dp/B0887P21Z2/ref=mp_s_a_1_3?crid=5CGRVH7FP7S5&dchild=1&keywords=samsung+256gb+micro+sd+card&qid=1630383270&sprefix=Samsung+256gb&sr=8-3
If you plan to copy a lot of stuff with the SD card in a PC the Samsung is worth the extra 2 dollars IMO.
Also, after using autoplugin for SD2Vita and having occasional issues I switched to YAMT(yet another mounting tool). I only switch 3-4 months ago, but I've not had a single issue AND my Vita boots several seconds faster. This is my personal experience, take it with a grain of salt. In a Retro Game Corps video Russ said that YAMT formats the SD card in the same obscure formatting standard that Vita memory cards use. I will never go back to autoplugin for sd2vita.