I’m sure we’ve had threads about soundalike bands; I’m looking for bands that are hard to keep straight because their names are similar.
My example is tough to beat, because they are the same genre (modern punk, I guess). Their music sounds somewhat alike, but I always mix up Against Me! and Rise Against. (For a third band that could kinda fit with these two but is not quite as bad, there’s Anti-Flag.)
Any other examples?
Gypsy and Gypsy. Both groups were active at about the same time (first albums 1970 and 1971, respectively). The latter group was from the UK, so was billed in the US as “English Gypsy.” I wouldn’t be surprised if the name confusion hurt their careers.
My favorites in this category are Three Days Grace, Three Doors Down and Third Eye Blind. Similar styles, although not identical. They also all became popular at roughly the same time.
The Who and The Guess Who
Unrest and Unsane. One of these bands has a video that is nothing but clips of skaters hurting themselves, but I can’t remember which it is.
The Verve and the Verve Pipe, even though their music styles are very different.
Nickelback and Nickel Creek, somehow.
Not really popular at the same time…
Third Eye Blind - 1997
Three Doors Down - 2000
Three Days Grace - 2003
Funny how, according to the bios, the American Gypsy was inspired by British prog-rock, while the British Gypsy was inspired by the '60s San Francisco bands.
Back in the Seventies, any time I mentioned the British folk-rock band Steeleye Span, people invariably assumed I meant Steely Dan.
There’s Dream Synicate, Dream Theater, and The Dream Academy (not to mention Dreams So Real, Tangerine Dream, and Eleventh Dream Day).
I’m off to listen to some REM Speedwagon…
Black Crowes and Counting Crows.
The Cure and The Cult. Not exact sound-alikes, but both from the same era.
Let’s not forget Seven Mary Three and 311.
The proliferation of ‘threes’ and such in the music scene befuddled me.
In the days of hair bands there was White Snake, White Lion and Great White. Not being a fan of the genre I could never tell them apart. I think one of them might have been foreign.
I also get the Pixies and the Pogues mixed up.
And don’t get me started on Radiohead and Machine Head. I know one of them has a homely lead singer. Oh wait . . .
And, from that same era, The Call.
Everlast and Everclear.
Everclear was top billed at our local huge musicfest last year. I was really confused about why they chose them/him–kinda depressing. I was much relieved when I realized it was Everclear and not Everlast.
Ironically, the headliner this year was Third Eye Blind. And Uncle Kracker played too, while last year, we had Cracker.
Splitting hairs. That’s about the same time, assuming you’re older than 18.
You forgot about Three Dog Night.
And whenever people start complaing about the Dave Matthews band I always think, “But I liked The Joker…”
I always get The Orb and Orbital mixed up.
Thankfully, the odds are extremely low that I’d ever wind up on Jeopardy with “British Electronica Bands of the 90s” as a category. 
I always mix up **Cowboy Mouth **and Cowboy Junkies.