Minibrute is an easy to use, simple monosynth, with keyboard, and absolutely no menus. Pretty damn cheap too.
Sp-404sx, and the other sp's, are really great pad based samplers, dirt cheap too. I absolutely recommend this over all other hardware, for realz though.
Maschine is dope, just worked it back into my setup after the 1.8 update. Thing is with maschine, if you have a good pad controller like, the padkontroller,

or maybe some high end mpd type thing with pads that actually work, and a daw with good midi functionality, you can have smoother workflow and more capabilities than maschine. With that said, Maschine has been my daw since working it back in. Not doing tracks in there, as that is challenging, but am making throw away beats, and having a shit tun of fun.