For small games, without a doubt, i would put a JSoD on the top of the list. He is a bargain and can be used for nearly every role (beyond breaking r&f units on his own).
Many people will in all likelihood say that a unit of 15-20 Saurus is something which they will not leave home without, but I would propose the opposite that 2 units of 10-12 skinks w/ a unit of 3-4 Kroxigors is the best basis for an army. Saurus, with their m4, low I, and large unit size, can be best described as an anvil unit. Against some armies, such as Dwarves, you could well get the charge off; but regardless Saurus are going to win through attrition. Meanwhile, the bait and break tactics of a Krox/Skink combo can allow the Lizardmen to play a much more aggresive game.
So, as a basis for an army, I would suggest a Scar-Vet blister, a box of skinks, and 3 Krox. From there you can invest in Saurus, but Terries, salamanders, steggies, JSoD, etc. all work best when using the bait/redirecting principle first learned through Krox and skinks.