Bitter's dominance is a fairly recent phenomenon; as late as 1929 it accounted for only 4% of output, with darker ales like Mild, Porter and Stout much more the usual tipple. The first great Bitter was India Pale Ale, brewed in the nineteenth century for export to India. It was heavily hopped, not for taste reasons, but because the hops helped preserve the beer on its long journey round the globe. However, the taste for hoppy, bitter beers developed from here. The IPAs we have today, incidentally, bear little relation to their original namesake which was much stronger and much hoppier.
Within the range of beers falling within the bitter definition, the variety of tastes and flavours is endless. Bitter derives its characteristic taste from the use of hops both in the boil and when added to the cask at the end of brewing. Hops, however, impart other flavours, ranging from herby/aromatic through to flowery and so the amount and type of hops is crucial. A lot of the Bitter produced by the big brewers are notably bland and inoffensive due to light hopping. The joke about the late, unlamented Websters brewery was that they only had one hop which they ritually dipped into each brew.
A poor balance of hop useage can lead to a beer which is bitter without having the more rounded qualities a classic Bitter ought to possess. A good example is Greene King IPA, especially when served fresh from the brewery. Unless properly cared for, this is a one-dimensioned beer with little to offer other than its bitterness. The use of hop oils rather than whole hops no doubt contributes to this.
"Drinking" Bitters come in the gravity range 3.5% to about 4% and ought to be refreshing, dryish and with a hoppy zing. Classic examples available locally include Adnams, Youngs, Nethergate IPA, Hobson's Choice and Woodforde Wherry.
Between 4.1% and 4.5% we have Best Bitters which are generally more complex. A variety of fruity, malty flavours comes through to counter-balance the hoppy immediacy of the lower-gravity beers, resulting in some of the trluy great ales. Timothy Taylors Landlord, for instance, has several times been Champion Beer of Britain and possesses a glorious aromatic quality mostly deriving from the unusual Czech-grown hops it uses. Fullers London Pride is another classic, beautifully balanced, rich and fruity. Nethergate Bitter also belongs in this category; though only 4% it has a complexity of taste which takes it out of the ordinary rating.
Sadly the bulk of Bitter sold in this country is feeble stuff, designed for easy drinking and making little impression between entering mouth and arriving in stomach. Mass-produced Bitters like Theakstons, Worthington and Flowers will never rise above the merely pleasant because the basic ingredients just aren't there.
Finally, if you do have a taste for truly hoppy beers, there are a couple of breweries that can be recommended whose beers can sometimes be found in the local free trade. Roosters of Harrogate brew gloriously biting ales with characteristically citrus overtones; some of their beers appear under the Outlaw label. Slaters of Eccleshall quite often deliver to the area direct and both their Bitter and Original are also way out there at the cutting edge.