As much as Andrea Dworkin and the "sex wars" of the 1980s aren't the worst place to get an idea of feminism, I think the earlier stuff is important too and that it is under-emphasized in comparison to either works of the "sex wars" or more recent works. I want to know if it's just me that gets this impression.
I think it's important to read the earlier stuff too. Very important. Sure, radical feminists were still figuring some things out then, but don't you want to understand how it developed? How they came up with their ideas and theories?
By "earlier stuff," I'd say I'm referring to things written during or before the early 1970s. The second wave didn't really start before the 1960s, but Simone de Beauvoir's 1949 book "The Second Sex" was a major influence on the early radical feminists, so I'd honorarily include it with other early second wave stuff.
Also, I want to say that I have noticed a major difference in the mood, which reflects the momentum of feminism. In the late 1960s, the second wave was coming into its own, consciousness-raising groups were forming all across the USA, there were protests and rallies and speak-outs; hell, some feminists even hexed Wall Street! But by the mid-1970s, momentum was running out. The wave had already peaked. A backlash was growing. The Women's Liberation movement was either dead or dying. So it's no coincidence that there is much more optimism in the works of the late 1960s. By the mid-1970s, things were looking bleak.
Do I have any recommendations? Yes, I do in fact. Here's where I'd start.
Notes from the First Year (1968, 32 pages)
Toward a Female Liberation Movement (1968, 35 pages)
Radical Feminism (anthology; edited by Anne Koedt, Ellen Levine, Anita Rapone; 1973)
If you're interested in whole books, then I'd say go for either the Feminine Mystique, the Second Sex, or one of the two main radical feminist books of 1970, Sexual Politics or the Dialectic of Sex.