The SM58 is a good mic (I have one), but being a dynamic, it has an innate disadvantage of not being able to capture fast transients as well as detail and definition in the high frequencies - it is great for vocals and a wailing guitar amp, though. A condenser is usually considered for detail and clarity, and it seems to capture more "air". My first condenser was a cheap MXL V63M that I find to be better for vocals and voiceovers as compared to my SM-58.
Among the budget to medium priced condensers I can recommend are the
Audio Technica AT-2020 ($99) and -4040 ($299), the Rode NT-1a ($199) and multi-pattern
NT-2a ($399). All these mics are large diaphragm condensers of good build and from reputable manufacturers. They all require pre-amps with phantom power; mic pre's from ART, Presonus and M-Audio are good candidates to choose from.
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