I've been posting a bunch of comments in response to people asking for positive reasons to vote for John Kerry, and Randomtask suggested that I make one of them into a diary. My apologies if that sort of quasi-duplication is improper (though I'm going to be mixing in a significant amount of new material).
The greatest irritation I've been "hearing" seems to come from people who feel that the only reasons they've heard to vote for Kerry revolve around electability. So for this diary, I'll restrict myself to non-electability-related reasons why Kerry would make the best President. I also see Kerry as the most electable candidate, but my reasons for thinking that can wait.
Some non-electability-related reasons to vote for John Kerry (in no particular order):
1. Kerry is the only candidate in the race with significant experience in both domestic policy and foreign policy. He won't need much "on-the-job training" in any field; he'll be able to hit the ground running, as it were.
2. Kerry has the best environmental record of all the candidates. He has a 96% lifetime rating from the League of Conservation Voters and earned the earliest endorsement they've ever given in a Presidential race. Some specific highlights of his environmental record include leading the fight against Republican attempts to weaken the Clean Air Act, being one of the first to threaten and then organize a filibuster against recent Republican attempts to allow drilling in ANWR, and authoring important 1994 amendments to the 1972 Marine Mammal Protection Act and a 1990 law to protect marine mammals from driftnet fishing. (People who think he's exaggerated his role on these issues should ask themselves why the LCV would have endorsed him so enthusiastically and so early if that were the case.) There's a lot more, though; those who are interested can look at LCV's summary webpage on him or the more lengthy PDF profile it links to.
3. Kerry has a solidly liberal overall voting record that's earned him a 93% lifetime rating from Americans for Democratic Action. For those who want a specific example of an important vote for an unpopular liberal cause, note that he voted against the Defense of Marriage Act-- which even Paul Wellstone voted for. He also voted against the 2001 Bush tax cuts, contrary to the claims some have made here.
4. Kerry's record has an element of economic moderate-ness very consistent with the successful Clintonian recipe for economic growth. He voted for not only Clinton's 1993 deficit-cutting budget but also the 1980s Gramm-Rudman-Hollings deficit-control law, and he favors free trade, albeit with labor and environmental protections built into any new trade agreements we sign.
5. Kerry's tax plan gets rid of the Bush tax cuts for the wealthy, but not those for the middle class. The middle of the Bush recession is not the most economically appropriate time to raise taxes significantly on most consumers; repealing the tax cuts for the wealthy is sufficient to get rid of most of the distributional unfairness from the Bush tax cuts and get back a decent portion of the lost revenue.
6. Kerry has more of a record of accomplishment in the Senate than a lot of people think. He spearheaded important investigations into the Iran-Contra affair and the Bank of Credit and Commerce International, taking on Republican administrations in the process. He's authored successful environment-related bills, cosponsored others, and played leading roles in the fights against rolling back many existing environmental laws, as mentioned in #4. In any case, I can't think offhand of many legislators with more than a couple of specific accomplishments in their names; most of being a legislator is working on and voting on bills that other people have officially authored. And in that respect, Kerry has done a lot of good over the years, as evidenced by his ADA and LCV ratings.
7. Kerry's Vietnam war experience means that he knows what war is really like, unlike the various Republican "chickenhawks". And Kerry's heroism as an officer during the war shows that as an executive leader in a crisis, he can make quick and courageous decisions.
8. Kerry's health-care proposal combines coverage for more Americans with a plan to control rising healthcare costs. I've been unable to track down the relevant link so far, but my recollection is that for this reason it got the highest rating of all the candidates' plans from some nonpartisan group that looked at the plans last fall.
In writing this, I haven't consulted the johnkerry.com website except in a brief attempt to track down an outside source, as I was concerned people might otherwise suggest that I'd compromised the authenticity of my "voice". I'm sure there's more there if people are interested. I suspect I may think of more over the next day or two even without looking at the website, but per Randomtask's request I wanted to put out what I've got so far.