Recording Bass Guitar

Often DI'd for the cleanest possible sound.
DI'd bass can lose power when placed in a mix. Amped tracks often sit better in the mix.
DI boxes allow high frequencies to be recorded, when an amp would filter them out. Use EQ to attenuate these, as they can stand out too much in a mix.
DI and amplifier signals can be mixed, or recorded to separate tracks for more control during mixdown.

EQ can sometimes increase clarity; the fundamental is affected from 125 - 400 Hz and the harmonic punch is normally between 1.5 - 2 kHz.
Most speakers need the bass to have significant energy in the 100 - 200 Hz and 40 - 80 Hz ranges.
Don't worry about over EQ'ing the bass; it's not a natural sound, so we don't have a predefined idea of what it has to sound like.
The bass can suffer from a varied signal output, with some notes sounding louder than others. Compression is often used to smooth out these levels.
Try a ratio of 4:1, a fast attack (8 - 20 ms) and a slower release (250 - 500 ms). Auto settings (if the compressor has that option) can also work well.

Most dynamic vocal mics have a low frequency roll-off to counteract the proximity effect; they are therefore lacking in low end.
A bass mic (like the AKG D112) can sound great, but have specifically tuned frequency responses and so might emphasise some frequencies more than others. Check that it's what you need for the track.
A loud amp will cause rattles on itself and in the room. It will also increase spill onto other instruments mics.
Condensers can sound great, as long as you're not recording something ridiculously loud. The frequency response often goes down to very low frequencies, and they also pick up the bass guitar's high frequency content very well.
Try to make tonal changes through mic placement rather than by using EQ.
Bass amps need to be miked from a distance of 6″ to 18″. 12″ is a good starting point.
The centre of the cone (dust cap) gives the brightest tone. Moving the mic off axis (towards the edge) gives a warmer tone.
The floor will contribute to the tone. Try putting the amp on solid floor or carpet; a PZM on the floor in front of the amp can work well. The amp can also be placed off the floor (on a chair, for example) to reduce the floor reflections.
The room's modes can affect a bass recording. Moving the cab can minimise the effect.
Distortion can work well, but be careful not to turn the low end to mush.

Mixing a DI signal with a mic on the cab can give the best of both worlds, but there are phase problem between the two signals due to the time it takes for the sound from the cab to reach the mic (about one millisecond per foot travelled).
To cancel this out while tracking, the DI signal needs to be artificially delayed.
Alternatively, record the two outputs to two separate computer audio tracks and align the waveforms.