My favorite are Tsukineko Dew Drops (Brilliance or VersaMagic). I find that they stamp a great, clear image, and the small size of the dew drops gives you numerous colors for the $$ (which is great for me because I rarely stamp). They are also great for inking the edges of paper/embellishments, and the small size is easy to work with (when stamping place the ink pad on top of the stamp instead of the other way around).