Need some help ID'ing...

I got these cacti's and succulents a while ago and have been trying to ID them, but I seem to be no good at this. So can anyone give me a little help? Especialy for the one on the far right because as you can see one of leaves (?) has fallen off and died.

 

1. Haworthia
3. Aloe spp.
5. Some kind of mammilaria I think.

The rest I'm not sure about.

 

I'm no cactus expert but I have a plant exactly like your number one, it is a warty/soap aloe, scientific namegasteriaverrucosa. Try this site: http://aggie-horticulture.tamu.edu/interiorscape/indexcommon.html.
Good luck on the rest!

 

No. 4 looks like a young Stetsonia coryne.

 

Either that, or Trichocereus candicans...