I am crazy about Compact Macs. My actual goal is to own every single version. (128K, 512K, 512Ke, Platinum Macintosh ED, Plus, SE 2x800k, SE FDHD, SE Superdrive, SE 1/20, SE 1/40, SE/30, Classic and finally Classic II). So to me they are worth buying. I know I'm crazy.
BUT, if what you need is a Mac to play games etc... I think you'd be better off with a 68000 Compact (Plus, SE, Classic) as some games kinda run better on those than on more powerful 030 macs. Since you already own an SE/30, I don't really recommend buying a Classic II as it's basically the same as the SE/30, except the Classic II's a bit less powerful.
You can get an SE for as low as $15.
http://maine.craigslist.org/sys/5895636624.htmlThese SEs are nearly indestructible.
The Plus is a very nice computer. It looks terrific and definitely 80s. But you'll need an external hard drive and the Plus can overheat very easily. And it demands a premium as well.
The SE and the Classic are pretty similar, except the Classic is plagued by those damn SMD caps. You'll have to get the Classic recapped (it will cost you a bit more)
If you want something different, go for the Classic as the SE and SE/30 look identical.
Every Mac is worth buying (I know I'm an Apple fan boy too), you just need to pick up the one that suits your needs most.