Proper use of any compressor/limiter in anybody's software package are generally more than adequate. Improper use of them is a typical problem with most folks that do not understand compression and limiting in general. Spending money on expensive plug-in blah blah ain't going to fix anything for you. Because if you don't know how to utilize the compression and limiting properly within your current software, no plug-in is going to make any difference when you use them incorrectly also. In fact those plug-ins can cause you even more abnormal sounding problems that you are experiencing currently. That's because they are extremely aggressive and are also modeled to create certain sounding characters for specific purposes. That requires a knowledgeable person to utilize. No magic pills are going to make any difference with improper operator error in their usage. A compressor limiter is simply there to enact a proper dynamic structure when utilized properly. I will lie upon a lot of included stock effects in numerous different multitrack audio packages without the need for any other plug-ins. I have other plug-ins that I have acquired for specific purposes. So even though I have those, I don't utilize them on everything. Most of the time I rely upon the stock effects packages that are supplied with all multitrack software. I know what kind of compression and/or limiting I want and how to utilize them for my purposes. Most of those are fairly adjustable in all sorts of realms, attack, decay, look ahead, ratios, which must be understood first before one can get an acceptable sound. And may also include adjustability within the gain reduction sensor where you can include high pass filtering which works very well on vocals. This means the compressor will not be quite as sensitive in the lowest of the frequencies which really has nothing to do with vocal recording. And it still allows all of the frequencies through even though the high pass filter is on the sensor not being a filter on the actual sound of the microphone. So it doesn't affect the microphones frequency response at all just what the compressor is working on. And the compressor doesn't need to see all of that needless low-frequency stuff at the sensor. So chances are there's even a preset that indicates that for you, within the stock compressor/limiter in your software.

Compression R Us
Mx. Remy Ann David

Very much agree that it's how ya use or abuse it. When i got my 414 my recordings sounded worse for a month or so, till i figured out how to minimize the unnecessary stuff the more sensitive mic was picking up. IMHO the best sounding stock plugins came w/ adobe audition 1.5 which i used for a few years. that said, after using PT, Reaper, Cubase, Ableton, Digital Performer, to various extents, they all sound OK. Each one kinda has a couple that are better than the rest of the pack, so it depends on what your looking for. A 'nice-ish' reverb being the weak point overall if you ask me. Which is going to be my next personal investment plugin-wise. There are just so many free plugins available in VST format it's ridiculous. I recommend a search of soundonsound.com 'reader remix'. Mike senior almost exclusively uses reapers stock/or free available plugins, to remix people's tracks. I like that concept because it levels the playing field (pluggin-wise), and show hows a working professional manipulates sound using stock/free stuff.
In PT enjoy the free izotope vinyl plug-inswhen it works w/ the tune, it's a cool one. other than that most of the free rtas i've tried are more wacky than utilitarian. 'maxim' is an ok free rtas, but i don't think it's no better than the stock limiter, and doesn't have any additional character.
Waves sound great, and are very expensive. Sonnox and McDsp are at the same level, lexicon too, from what i've heard/read.
You need to know 'what' you expect your plugin to do, before you buy like 8 in a bundle and really only use one or two. Character? Transparency? Surgery? Destruction? Generally, i'd pick out a few individual plugins and one small bundle. My shortlist- waves CLA bundle (UA compressors/Neve eq), a decent verb (softube/lexicon) to put on a couple of returns, the L2 limiter on the bus, for a quick mix.
One thing to consider, is character= cpu power. So i wouldn't expect to run these on every channel of an average mix, on an average cpu.
The biggest difference in quality you will hear is in the raw tracks. Especially now where anyone q/ a credit card can get a cpu/bunch of plugins, i think that the sound of the raw tracks/room/input chain, is going to separate things, far more than so and so's 1176 model vs. the other model.
lastly, you might want to checkout a focusrite liquidmix, they have problems once in a while, but they're pretty cheap, and have a few nice sounding models, and doesn't tax your cpu. among my fav's on that one are it's la-2, and ssl quad bus compressor. Not everything on it sounds great, but there's enough good character pieces to justify it's price tag, plus, it's DSP. Try the free demos of anything you can to make sure it'll work. It's quality over quantity.