There is no substitute for a sectional certainly. But from AOPA flight planner, I print out the route map summary with 30-minute waypoints, then the sectional pertinent to the destination airport from AOPA or Skyvector.com (as the previous poster said) noting the terrain for arrival and departure. Also I print out the airport diagram and AFD page (from airnav.com) and review it ahead of time.
FYI I have a Garmin 430 and Garmin 496 with airport diagrams. But I prefer to look at all this before getting into the cockpit, so the Garmin makes more sense during flight and I know what to expect when flying into new airports.
I've tried WAC charts, but they're not the same as sectional...don't have as much detail. And you're paying for it...
If you do buy a sectional, try to volunteer for a sector where you can re-use the charts several times. For me that's the Chicago sectional 90% of the time. The fringe stuff I print out from above sources.
Hope that helps.