That said, there is also quite good control in their encounter powers. For instance, Orbmaster's Incendiary (or Icy Terrain) drop a bunch of monsters prone. If you have Enlarge Spell (and you should), that's a 5x5 area where you throw things prone. That is good control; you just need to make sure your allies are not in the way (which is doable with good tactics). Other encounter spells that immobilize, daze, or blind enemies, preferably as an area effect, are great control.
Minion killing should not be your main role. Minion killing is a side effect, and your area effects should already take care of most of that. Here's the key: you as the player, and your party members, may not necessarily notice how much of a nuisance you're being. But the DM will! A well-played wizard will rip the DM's strategy to pieces.
And Thunderwave? It's one of the best at-wills in the game. The only thing is, you need to have some interesting place to push the enemies to. Many DMs will have combat maps involving fire, cliffs, or other hazards; guess where you're going to move people. If the map is not obliging, feel free to drop a zone daily (or encounter power like Grasping Shadows) and start chucking enemies into there. I've spent entire combats casting nothing but Stinking Cloud on turn one, then TW on every subsequent turn.