I have this problem that is really annoying. When I play a song for example, I can't get the sound consistent like in songs I hear on the internet for example. Like, if I play a chord (perfectly, for example) and I need to switch, the sound from the chord will most likely stop, or reduce to a open chord because I basicly pull-off, when I lift my fingers to switch to another chord.

It's really annoying me, but i'm thinking it's the guitar, because it's one of those guitars you buy in a "beginners package" or "gig bags".

Was just wondering if anyone could give me some input on if it's the guitar or if it's my playing (and how to fix, if you're really nice ).
The pull off part youre gonna have to learn to control, and maybe you just don't switch chords quick enough and a lot of people do a quick mute with the left hand while switching some chords to keep the fluidity going...part of it may be the guitar but you should be able to overcome it
'I love her, but I love to fish...I'm gonna miss her"
It's not that I really pull-off, but i've tried fixing the problem with that approach, but didn't turn out so good (the pull-off occured :p). When I lift the string slowly, I get a buzz on some of the frets actually, but I don't mind... Until I get better gear, I am not gonna try and do so much with the current one I have.
Try playing with other peoples' gear. Half-split the issue between your guitar, your skill, or your effects/amp. You'll be surprised how polished your playing will sound when combined with the right combo of delay, reverb, compression, etc. So try your guitar with a different high quality amp/fx combo, or try a different guitar with your amp, or take your guitar/amp to someone with some high level skills and listen to what they can achieve with it. Get their opinion on your gear, including how high the action is.

I played for years on a crap amp with a crap guitar until I was fed up with my perceived lack of progress/ability. I quit playing for many years. Then I bought something as simple as a digitech rp-50, and discovered a whole new world of sound that made my playing sound instantly better, and it further grew my ability due to renewed interest.