I totally agree. I love that the simple phrase 'Tiva 4 eva' can express my opinion so entirely. GO TIVA! For all you Tate fans who are really unsure or angry at Tiva, I would recommend that you visit the author DrawMeASheep on fanfiction.net. Here's the link to her page: http://www.fanfiction.net/u/1145030/DrawMeASheep
She has about 73 stories and most of them are Tiva. Before you judge, read some of them. If you can still argue that Tiva isn't both poignant and downright sexy, I concede. But I gotta argue that the Tiva relationship has so much more depth to it than Tate: Tony and Ziva complement each other and they help each other grow beyond the emotionally distant assassin and the commitment-phobe playboy into really touching characters...at times....other times they are childish teenagers ruled by their hormones. I may have shot myself in the foot with that last sentence, so let me explain: Tiva can be really deep and tragic, or it can be silly and fun. Tony and Kate just didn't have that kind of depth to their relationship.