In all honesty, I feel that if a product is not illegally ripping off another company (like Shifty did to many of TLC's sets), then you should judge them solely on their quality. And no, that doesn't mean that you should go "hey, most people say they're crap, so they must be poor quality and I shouldn't even touch them." If you really want to back your comments up (positive or negative), you need to actually experiment with the pieces, like I have.
And actually, Megabloks isn't as bad as some of you guys make it out to be. Sure, the quality is definitely lower than lego, but it's improved vastly from their early days. Plus, Megabloks does have some very interesting pieces - the walls used in the Dragons line have a great texture and design, for example. And concerning acessories, I think they've really done an execellent job. Their fantasy themed lines have some very cool handweapons, and those guns that were posted above look nice too. Plus, Megabloks actually had the guts to produce a military themed line, which TLC will probably never do.
Of course, my opinion about them is rapidly changing, as they seem to now be focusing less on their stud based play line and focusing more on novelty toys like Magnetix, Struxx, and Neo Shifters, which IMO is just an obvious cash in on Bionicle's success. Still, I honestly feel that anybody who doesn't at least try out Megabloks toys has no right to bash them.
*prepares to get bashed himself*
Very well said Grevious.