Fantasy art.

If you're talking about media, 1 and 2 would be done with oils if painted for real, 3 is airbrushed, 4 and 5 could be a number of things.

If you don't mind editing a ton of layers in photoshop, the smudge tool can give some very good approximations of oil paint. Don't forget, oils are popular because of their slow drying time, meaning you can 'work' the paint into previous layers (blend and smudge), as well as glaze (thinned paint over the top to give a caste). All can be done with layers and the smudge tool without using any of the filters.

If you intend postworking images like that, I'd consider investing in a good tablet. Much better control than a mouse can give.