All depends, do you want a lizard to handle or do you just want a cool lizard to watch and keep? Unfortuently for you majority of all the lizards you can keep in a 2ft enclosure are not very good for handling. So if you want something to handle you are best off looking at getting a larger enclosure.
If you don't want to handle though you have quite a nice selection of geckos and small skinks that will happily live their entire life in that size enclosure. I would highly recommend that you look into the different small skink species that are available in the hobby. They are all diurnal and very active during the day so they make excellent display animals. They can be quite flighty at first but they do eventually become rather bold and happy for you to watch them. There are quite a few skink keepers that have a large variety of species available to keep, you just have to track them down and have a chat which is not to difficult. If you are interested in keeping some of these species I would highly recommend that you purchase or borrow a copy of "A guide to Australian skinks in captivity" by Dr Danny Brown. It is an excellent book that details the care of all the different Australian species available.
Geckos are another good choice for that size tank. Unlike skinks though geckos are primarily all nocturnal so they are not great for daily viewing. They are rather simple to keep though and there is lots of online care sheets and books that detail the care of all the different species.
Hopefully this is some what of a help in your choice of a new lizard. Have any question feel free to ask.
Cheers, Cameron.