Many other birders have talked about that one bird that was their "starter bird." You know, that bird they saw early on that peaked their interest in birding. Although I am a new birder and have hundreds of birds to see in the future (hopefully!), my starter bird was the Red-bellied Woodpecker. I remember the first time I really got a good look at one through a pair of binoculars. I was so awed by their beautiful barred backs and red caps. I suspect I'll always enjoy seeing these guys.
A close second is the Black-capped Chickadee. They're such charming little birds and have a wonderfully social personality. Every time I see one flitting about in the trees or at my feeder I smile.