For just one mic, the
Blue Icicle is good, but it's not got any extra outputs such as speakers or headphones, it's purely a little preamp and A/D converter
the
Alesis io2 is more comprehensive, 2 in's on either xlr or line/instrument with phantom power where needed, 2 out's, headphones, MIDI and SPDIF. No idea how much it is states side but's £99 this side of the pond.
As always, there's a load of questions i should ask to help better determine your actual needs from an interface. What do you record? usb or firewire? how many inputs do you need?