Pro Tools certainly holds the crown for "industry standard"; however, though the projects are compatible, be aware that Pro Tools and Pro Tools LE/M-Powered aren't the same in a lot of ways, beyond the usual "full version/light version" differences that are to be expected. A lot of Pro Tools power comes from the tight hardware integration, which is absent from the M-Powered lineup.
For a "Traditional Sequencer", you're spoiled for choice these days. I do agree that often whatever "comes with your card" is more than adequate--and also more powerful than we had a mere decade ago! For people that have gear that comes with Sonar LE, I think it's the best of the "crippled version" bunch. Cubase LE is acceptable, and Tracktion (which comes with Mackie interfaces) is the only truly full-featured of the bunch.
If you're willing to take the time and possibly make an extra purchase, by all means do not walk past Reaper, which has really come into its own since this thread started. I'm a Tracktioneer at heart, but I can't stop myself from recommending Reaper to people on a budget, looking for an alternative, or who like to be on the cutting edge (the developer is a madman cranking out update after update).
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Drak-- by all means, I'm no expert... I'm just a hobbyist who has spent far too much time researching and mucking around. But I for one would like to hear about your adventures, and if there's anything useful I can add to the conversation, I'll chip it in.
Greg