What I
aim for is "solid," "locked-in" and often "driving" (which does not mean rushing). Timing is king. The wrong note smack on the beat is far less destructive than the right note placed sloppily just before or after the beat. Rhythmic subdivisions are extremely important--it's not enough to just hit the one and three on the money. Your fills and pick-ups also have to be in time with the high-hat and other instruments that are hitting those sub-beats as well.
Groove is sacred, and the root and fifth are holy, especially on beats 1 and 3 in rock, country, blues, r & b and lots of jazz. When I'm playing in the cocktail trio with vibes and sax (no drummer) I include more things (usually major or minor thirds) that emphasize a certain feel or emotion, but try to never compromise the rhythmic foundation or interfere with the soloist. Generally a less-is-more approach, but not fanatically so. Some of my heroes (Cogbill, Jemmott, Jaco, Pino) are very busy at times in ways that establish incredible grooves, so it's always a challenge deciding whether a busier line will enhance the groove or just bog it down.
Whether I accomplish those aims, of course, is another matter and probably more for others to say, not me

When I listen to recordings of gigs, I often wish I'd kept it even simpler. Some of the busy lines I've chosen sounded like they established wonderful grooves at the time, and on playback it was clear they were bogging things down:-/