I’ve been taking Nature’s Bounty because it was the only liquid b12 I could find at the pharmacy at that point, but it works really well for me. My doctor told me to take liquid because it absorbs quicker than a tablet/capsule. If you can only find tablet, I would recommend one you dissolve under your tongue versus swallowing.
For people who are vegetarian/vegan, I would say to make sure the brand you choose specifies if it’s vegetarian/vegan friendly.
Also if you’re unsure about your vitamin/mineral levels, I definitely recommend scheduling testing through labfinder.com or asking your doctor for a panel.