Actually, I thought about that a lot. Especially when it comes to Bangel and Stelena (Stefan and Elena). I even made a list on tumblr on couple of stuff that are similar.
Stefan gives Elena the necklace with vervain so Damon can’t compel her = Angel gives Buffy cross necklace that saves her life.
After they sleep together for the first time, something bad happens. Elena finds Katherine’s picture and almost gets herself killed = Angel looses his soul and starts killing again.
Elena makes Stefan drink her blood so he can get better = Buffy makes Angel to drink her blood to survive.
Elena: It’s you and me Stefan. Always. = Angel: You still my girl? Buffy: Always.
Stefan knew Elena before he actually met her when he saved her life = Angel knew Buffy before he met her, he watched her slaying her first vampire.
Stefan goes without his ring outside and waits for the dawn, he wants to die because of the past events but Elena stops him = Angel goes outside and waits for the dawn, The First is torturing him because of the past events but Buffy stops him.
Before Elena goes with Klaus, she tells Stefan “Close Your Eyes” = Before Buffy kills Angel she tells him “Close Your Eyes”, which is also their theme song.
I don't mind it, though. And I don't think they're trying to rip Buffy of.. I mean, those are two very different shows, with different vampires and different main heroins, so little similarities really don't bother me.. to be honest, sometimes I enjoy them.
And yes, scenes are similar. Buffy tells Angel to close his eyes, and when he opens them there is a sword in his torso and he's gone, Elena tells Stefan to close his eyes, and when he opens them, she's gone. But I think 'Close Your Eyes' has a deeper meaning in Buffy, and the talk about Bangel pulling it of better.. well, it's all more dramatic with them. When we compare the scenes, the one in Buffy is better, because it's a turning point.. Angel didn't know what's going on, and Stefan knew once he opens his eyes, Elena will be gone. As much as the scenes are similar, they're different for so many reasons.