For something as important as voting, how about paper only?
We actually have solutions that are much better than that. This wasn't true a few years ago when the whole voting machine fiasco started, but that discussion provoked a fair amount of research into secure voting systems, and security and cryptography experts have proposed a number of systems that provide verifiable end-to-end integrity. Each voter can verify that his or her vote was actually included correctly in the final count -- but without being able to prove to anyone else how he or she voted (important to mitigate vote buying/coercion). Each candidate/party can fully audit the ballots before the vote and the count after the vote, and audit results are provably correct.
The most thoroughly developed system is Chaum and Rivest's (this is the Rivest who is the "R" in "RSA") "Scantegrity" system. It actually does use paper ballots, slightly modified traditional "Scantron" forms. Rather than just filling in the bubble with a #2 pencil (though you can do that, and that will work, and it will only sacrifice one form of verifiability), instead bubbles are filled with a special marker that reveals a code. That code can be recorded by the voter and used by the voter after the election to verify that the voter's vote was counted correctly. Ballots are counted by normal Scantron scanners, and can easily be verified by hand.
But, thanks to the additional auditing steps (which rely on serial numbers on ballots and some carefully-defined processes) it's not possible to inject additional ballots into the process (no ballot box stuffing), nor to "lose" ballots, without detection. The system does make allowances for absentee and mail-in ballots, and has been used in a real election to verify that it's fully practical.
For more details about Scantegrity, see http://scantegrity.org./
And another thing, we should really do vote-by-mail nationwide just like Washington state does it.
There are signficant risks in that. OTOH, it doesn't seem like Washington is actually seeing them. Still, I'd move very carefully on that one.