A Sony TCM-200DV works great for me. Analog tape recorders record with much higher quality than your common handphone/mp3 player recorders. Place it high away from cymbals as mentioned earlier on, and later EQ the track using Audacity, giving bass boost and cutting treble.
It also helps if you obtain an omni-directional mic so as to better capture the frequencies from the various amps that are usually placed around the room in a circular fashion.