Ah, the eternal question.
I think "Outing the Family" is the best. Like Dan said, bonus points for the creative use of backgrounds. Very clever.
I also don't like drug strips, because they're way too easy and overdone. Swirly blue background + randomness = barrel full of dead fish, but not humorous. However, I think the line "I can taste what you're thinking" is pretty damn funny, making "Don't try this at home" one of the best drug strips I've yet seen.
"Consecutive Run on Life Sentences" is a great title.
I always love some good Microsoft-bashing. "You have the right..." has a funny premise, but I feel like it could be delivered better. MS' attitude/reaction could have been more severe/immediate/absurd. I might have done the third panel something like this:
Letter-reading guy thinks: Not owning a computer is not an excuse. An axe-wielding maniac will be coming door-to-door to sell you one.
Invisible right character: Knock, knock.
or this:
Letter-reading guy thinks: Not owning a computer is irrelevant, as it does not preclude you from owning a copy of any computer software.
Of course, you should ignore my advice or opinions if you don't like the sort of strips I write. My sense of humor is frequently not in sync with that of the general population of this site.
If your strips came up for me to vote on, I'd probably give most of them about a 5, which is my standard score. So, you're doing OK.
Think about participating in the contest that Gabe is organizing (see the "Comic Contest?" thread). It might be good practice.
And welcome aboard.
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The what mentioned above is total fiction. Please don't take it seriously!