Order of investments

I was eating lunch the other day and this topic came up. Actually this topic seems to come up about once or twice a year or so, probably around the time of paycheck contribution elections. When the topic first came up, I just listened and couldn't make heads or tails about why its smarter to go one route or another. Now I feel like I know exactly what to do, read on:

401k with employer matching should be first, this is 100% ROI plus an average of 10% annually or so. Not only is this tax deferred (meaning compounding works greatly in your favor) but it also lowers your taxable income. :)
Putting in more than your employer will match to should be further down the list.

Second is definitely an employee stock purchase plan. My company offers a 15% discount at the offering period, with two offering periods a year. Some companies make it even more worth your while with various options or the like. So if I can go without 10% of my salary for 6 months, I get 1.5% of my salary free two times a year. Since you can take the principle out at every enrollment, I can count this as a 30% APY on 10% of my salary. A $60,000 salary would net me $1,800 a year. Thats a nice Christmas bonus! If I let the first $900 ride on an average of 10% stock increase, its an extra $45. Of course the 15% is taxed as normal income, and I'd have to pay capitol gains tax on the $45 if I took it out before having it a year.

Third, if you plan on having a larger income when you retire than you do now, you should max out your Roth IRA before contributing more towards your 401k.

As an important disclaimer I'm not a math wiz nor do I claim to know all the tax implications. Please feel free to add to the comments if I make any mistakes!