The good thing about the different varieties of hay is that it's a great way of encouraging buns to eat more. Because wild rabbits graze on grass all day, and buns often don't have this chance because they're in a hutch or indoors, they need to be eating as much hay as they can, for healthy teeth and to keep their digestive system going and working fine.
All of the above hays are great for rabbits, and have different properties. Hay like timothy hay is great for the back teeth because of the way it is, it is more abrasive than regular hay, so especially good for rabbits prone to spurs and other teeth problems.
Oxbow isn't a type of hay, it's a brand - they do timothy hay, orchard hay, alfalfa, etc.
Meadow hay is probably the most easy to get hold of, and the cheapest. It's what pet shops sell most of, although usually petshop hay isn't the best quality. If you have room to store it, getting a bale of meadow hay from a farm shop is much cheaper and the hay is usually a lot better quality than what petshops sell too!
Timothy hay and orchard hay are great but can be quite expensive so you might prefer to keep it as an occasional treat, or to mix it with meadow hay.
Alfalfa hay is good for growing buns as it's higher in protein but isn't ideal for adult bunnies as it's too high in protein and can cause problems. The same applies to dried grass too, though you can feed more of it than alfalfa safely.
You can also get shortly chopped hays, which are quite good too - mine love the timothy chop from Bunnybasics, and it's good as it encourages my incisorless buns to eat more hay too.
It's up to you, and will depend on what your buns prefer and what you can get hold of more easily, but I personally feed my buns a half and half mix of meadow hay and Bunnybasic's timothy hay. Currently I get the meadow hay from a petshop as I don't have the storage for a bale but will be hopefully getting some from Greenfields Rescue, and once my bunny shed is done I will have the space to buy a bale. But right now I just make sure I search through for a nice soft, fresh, green looking bag at the petshop. They also get the timothy chop, and occasionally a bowl of dried grass (like the high fibre grass from Bunnybasics, or Readigrass)
They also occasionally get the timothy hay cubes from Bunnybasics (though obviously the incisorless buns don't have these!)
Hope that helped!
