This is yet another contribution to Tali's awesomeness and greatness. There are probably millions of things like this over the Internet, but I just wanted to add my piece of highly subjective opinion and say (again) what I think about Tali, why is she the best character in Mass Effect games for me and, possibly, the best female character in the whole history of gaming. Be warned, then, that these words are an opinion from a male Shepard perspective and my own views of feminine attractiveness and sexuality, therefore they may appear displeasing or even insulting to some of the beautiful half of humanity, not to say some of the other half will just plainly disagree with me. I will try to write this in the most delicate way though, but, just in case, don't be insulted by my words – it’s just an opinion as I said.
So, why is Tali'Zorah nar Rayya is the best character in Mass Effect? I will try to describe it from different points of view.
First of all, Tali is one of the two characters (the other one being Garrus) who really stands by your side from the very first game of the trilogy till the final battle in the third game. Who of us doesn't like it when a notable character from one game shows up in the sequel? Even if it's something brief, like mentioning him/her in some texts, or even if such character isn't significant to the main plot of the game. And what about playable characters who joins us on our adventures throughout the whole series of the game? Especially, if you like them from the beginning? I believe such things are one of the reasons why we love games like Mass Effect.
Second, the romance line with Tali seems to be the most properly developed and interesting. I was really disappointed when I learned I couldn't romance Tali in first Mass Effect. Then, after beating the first game and playing through the second, I was pleasantly surprised when it got clear it's possible to romance her. I must admit Bioware did an exceptional job here – the explanation of how Tali admired Shepard from the beginning, how she cared about him – it just fits perfectly into the game and makes Tali and romance with her more realistic and alive. Bioware most likely didn't plan this, but still, it is one of the points which makes Tali the best character in Mass Effect for me.
Of course, Tali wouldn't be Tali without her personality. There is really not much to tell here and it's very difficult to describe without such terms as ‘sexy’, ‘badass’ or ‘cute’. But so she is. Tali is sexy – just look at her body (I won't mention her hips – you already know it all). Badass? Sure – shotgun, deadly tech skills and high intellect. And for the cute part I've already ranted somewhere else. All these features alone don't make Tali, but together they do. It just will take too many words to describe Tali's personality for what it really is – better to play through the game to know her. To sum it all up, Tali is probably a perfect woman – too bad there aren't anyone like her in real life. Just joking:)
So this is what makes Tali the best character for me and not only in Mass Effect games. I really can't think of any other from the long list of games I played in my life who'd get even close to her. Tali is simply awesome, touching and real, and if you didn't play Mass Effect games she's one enough reason to give it a try.