Ah, the "homebrew taste." This is interesting, because my brother, still a noob, brought some bottles of his homebrew down from Kentucky, and the same weekend, we checked out a beer festival and sampled some brews from the homebrew stand. Damned if they didn't have that exact same flavor characteristic. I'd call it bananas with some phenolics and fusel alcohol. Drinkable, but only to a point. Mostly, this happens because the yeast are fermenting in a sub-optimal environment.
Here's what you can do to cut back on those "homebrew" flavors:
1. Pitch more yeast, even dry yeast. It is much easier to under-pitch than it is to over-pitch.
2. Ferment colder. Do whatever you can to get your temps down, even if it's just ghetto swamp cooler (wet t-shirt/desk fan combo).
3. Shake your wort vigorously for 5 minutes before pitching.
4. Re-check your sanitation practices. Try switching from star-san to iodophor, or boiling your equipment (the stuff that can handle a 15 minute boil, that is). If in doubt, sanitize. It's possible some of these "homebrew" flavors can come from a stray bug getting a shot at your wort.