What cameras are comparable to the Canon T3i?

Other than the Nikon D5100, of course. Also, preferably a model that is more inexpensive, though I'd like to hear any other suggestions C

You can also look at the K-7, which compares more to the Canon 60D, and is about that same price ($1200)

the Pentax K-r, which is $700

Nikon D3100, $700

Canon T1i, $700

You will have to lower your expectations and look at the Canon T3 or Nikon D3100

The T2i is comparable but a bit less. Same goes for the Panasonic GH1. 60D is a bit more, but has significantly upgraded build quality, longer battery life, faster shutter speeds, higher ISO & better AF.

I'll chime in with the T2i. It's nearly the same camera except for not having a swivel screen (a fixed one instead), and it doesn't have that wireless flash gadget of the T3i. If you ever need the latter, then radio triggers are a good alternative.

So… Basically the T3i was just a small modification of the T2i that came with quite a price hike.

D5100
Pentax K-r
Pentax K-5
Canon EOS 60D

60D has the same sensor, just better body, top LCD screen and faster AF. D5100 is the same as T3i, while K-5 from Pentax is somewhat faster.

Here's a DSLR Buying Guide - http://www.the-dslr-photographer.com/2009/11/which-dslr-to-buy/