It's a flavored beer in the same vein that a wine cooler is a flavored beer. I like it mostly because of its sweetness and carbonation (or whatever makes it fizz/bubbly). If that is technically what an alcopop is (never heard that term before) then I guess we're both right!
I see that taxes on wine and sprits in the US vs taxes on beer mean that wine coolers contain no wine (likewise stuff that in the UK would be spirits and fruit juice/juice substitute), but use un-hopped beer as a base. When I hear the term 'wine cooler' I understand some kind of drink based on fermented grapes (wine), rather than fermented barley.
http://en.wikipedia.org/wiki/Alcopop - I think it's more a UK term, it's definitely not an industry one, but it's the common term for those kind of things in the UK.
"In Europe and Canada, alcopops tend to be pre-mixed spirits, including vodka (e.g. Smirnoff Ice) or rum (e.g. Bacardi Breezer). In the United States, on the other hand, alcopops often start out as un-hopped beers, depending on the state in which they are sold. Much of the malt (and alcohol) is removed (leaving mostly water), with subsequent addition of alcohol (usually vodka or grain alcohol), sugar, coloring and flavoring."
They are OK, but if I want a sweet drink, I go soft or have one of the sweeter brands of cider - most likely pear cider, rather than apple as the apple stuff tends to be not very good if it's sweet (teenagers in the park drink before alcopops came along).
Every time I've had one of the "common" household beers I can only think "God, this stuff is horrendous" and only choke down one or two sips. I'm nearly 21. Were I to start drinking, is there any sort of beer that would be better to start with than that? (I've tried Smirnoff Ice and didn't really like it either—too sour.)
Common household beers in America are pretty ghastly. Palettes develop and you learn to like stuff. Looking at what you're saying, try something European(-esque) that's wheaty or fruity (or both).
For the beer geeks - there's a gastropub (ie a pub that specialises in food more than being a bar) near me that serves 83 (IIRC) different types of beer (the cask ales rotate, like in many English pubs, so I'm only counting that as one, though there's probably two at any one time). You won't get most of these in the States, and most of them are expensively imported. Also has a guide to which beer to drink with what food:
http://www.sausagetreepub.co.uk/Beers.asp . For Scott, something like Hoegaarden is the kind of thing I'm recommending - it's what got my brother into beer.