IMHO you won't find anything as good as IM...those guys are *the* most innovative, entertaining group in trance today AFAIC. So it's all downhill from here.

j/k You can find trance reviews (of...umm...varying quality, let's say)
here,
here, and
here.
Here are some groups I'd recommend trying out (you'll have to decide for yourself whether they're "beat-friendly"):
Astral Projection -- arguably the most famous name in goa/psytrance, and with good reason...though their sound has grown a bit stale recently IMO
Chi A.D. -- have some really good older tracks like Exit Eternity, Eye Am the I & Astral Warrior
Cosmosis -- try Gift of the Gods for a typical example of Cosmosis's distinctive sound
Etnica -- Italian group...again, mostly older "classics" like Starship 101 and Party Droid.
Hallucinogen -- was doing twisted sounds long before IM came along. The same guy also does ambient tunes as Shpongle, if you're into that sort of thing
Holy Men -- these guys are the archtypical group from the "nitzhonot" scene in Israel...meaning they do "uplifting" trance that includes a fast beat and lots of blippy sounds. It's very different from any other trance and many people *hate* these guys with a passion so consider yourself warned.
Juno Reactor -- I like JR b/c they aren't afraid to reinvent themselves and stay fresh...and because of that they do end up with a lot of poor tracks IMO, but plenty of unique sounds as well.
Koxbox -- progressive trance...not my cup of tea but plenty of goa fans seem to enjoy this style as well so WTH do I know??
Man With No Name -- again, not my favorite (I can't listen to more than a couple MWNN tracks in a row before losing interest), but he is popular so give him a try
MFG -- dark & bass-heavy...I love it
Pleiadians -- same people as Etnica IIRC...their album I.F.O. is widely considered one of the greatest trance albums ever *as a whole* (I mean listening to it non-stop from start to finish)...every track is good and they really build off each other well.
Shakta
Shidapu (or
Shiva Shidapu) -- this was the predecessor of Infected Mushroom, with some of the same people involved...good stuff, and you can definitely hear the similarities to IM
X-Dream -- dark sounds, but in a different way than MFG. Again, I'm not a big fan but they have a large and devoted following so give 'em a whirl.
Of course, find at least 5+ tracks from each to make sure you don't accidentally end up with their worst (or misrepresentative) work and get the wrong impression of their style. And remember that some of the best tracks come from "one-and-done" groups, or compilations so don't neglect those.