We can start a destroyer thread too, and other ship-types as well! My favorite light cruisers are either the Brooklyn class, or the Omaha class....
As for heavy cruisers, the more I think about it, the more I like the Takaos.... An enormous amount of firepower, heavy torpedo armament (the 'Long Lance' was the best in the world, good armor (except on the turrets), long range, and very fast... Hard to beat! In fact, the US 'Alaska' class battlecruisers were designed specifically to deal with cruisers like this....
Someone earlier (Effendi?) mentioned that the heavy cruiser in many ways replaced the battleship during WW2, but I'm not so sure the analogy is quite right. Instead, I would say the heavy cruiser replaced the battlecruiser, as the concept of high speed, heavy armament and relatively light armor is more in line with that initially proposed for the battlecruiser. By the time of WW2, battlecruisers (either old and refurbished, like the Kongo's and Renown's, or new, like the Scharnhorsts and Dunkerque's) had really morphed into the 'fast battleship' role, and thus were not really available for the role of scouting, commerce-destroying, and point defence. I think this was partially a result of combat experience in WW1, but also because of the severe reductions in the sizes of fleets after the Versailles treaty, London and Washington conferences. There simply weren't enough battleships around to form fleets and squadrons that might require really powerful scouting/screening forces, and this role was taken over by the heavy and light cruisers, while the battleships were carefully preserved for individual carrier TF protection and shore bombardment duties.....
This raises a couple interesting questions......
First, if the various treaties and conferences hadn't taken place, or had failed to limit battleship construction, and/or allowed existing battleships and battlecruisers of WW1 to be preserved instead of scrapped, how would that have altered the makeup and employment of WW2 naval forces?
Second, if a sufficient number of battleships/battlecruisers had been available in WW2 to make up squadrons and fleets like in WW1, how would that have affected the notion of overwhelming 'carrier superiority?'
In answer to the first (and conveniently ignoring the economic hard facts of the Great Depression), I suspect that many of the naval forces centered around heavy cruisers in WW2 would have been composed of battleships, and in fact, the concept and development of the heavy cruiser might not have arisen at all! Engagements between heavy (armored) cruisers and dreadnoughts in WW1 proved conclusively that heavy cruisers were pretty much worthless when confronted by dreadnoughts (SMS Scharnhorst squadron vs HMS Invincible squadron), and no further cruisers of this type were built by anyone until the post-war conferences severely limited the production of battleships/battlecruisers (and much more to be said on this topic!).....
In answer to the second, I suspect the impact of the aircraft carrier might have been much less, and certainly not enough to warrant the abandonment of the battleship concept. With enough battleships in a squadron, their AA capabilities could well have staved off wholesale destruction by carriers, and certainly, carriers without battleships were incredibly vulnerable to aircraft attacks themselves (carrier AA defense was the primary activity for the US fast battleships in WW2, and they performed magnificently in this role). In virtually every case of battleships caught at sea by aircraft, they were either alone, already crippled, or completely without any supporting aircraft. The Japanese tried 'battleship mutual support' at Leyte, but of course by this time there were just so MANY US aircraft in the air and so few Japanese, that the mission was bound to fail in any case. That said, Admiral Kurita's 'Northern Force' of five battleships managed to make it to Samar and engage the US 'Jeep' carriers, losing only one battleship (Musashi) along the way due to US airpower (and several heavy cruisers from US submarines), despite having virtually NO air support at all! My guess is that if Kurita had had the kind of friendly airsupport available only a year prior, his mission might well have been far more successful, and perhaps might have generated the kind of 'what if' battle with Kincaids' squadron of old US battleships so beloved and and argued over by strategists for the last 60 years!