Don't worry too much about orientation. Unless you are able to mount an HF dipole very high, you won't see all that much directionality. 20 meters is pretty much a given, being the most active band, probably offering the greatest variety of activities to survey. From there, it depends on your interests. But note that a 40 meter dipole will also work on 15 meters, so you get a twofer out of that one.
A multiband fan dipole is another option. More wire but one feedline, although they can be tricky to get all the bands matching well.
There's a variation on that theme at:http://www.eham.net/articles/21407
The classic advice is the dipole cut for the lowest frequency and fed with ladder line and a tuner. I'm assuming you figure the tuner costs puts it out of play for now, but it's a consideration, and you might run the numbers on what you save in coax feedlines and misc hardware and see if it's more workable than you think. Used tuners can be had for around $50. You get every band from the cut frequency up. 100 feet of ladder line is under $20. You can scrounge wire from most metal recyclers where the commercial electricians have dumped left over rolls with as much wire as you're going to need. It will probably be the one antenna you always keep in service, no matter what else you put up some day.