Well the dresden books are okay, good for a laugh and full of big bangs and explosions but imho no where in the same league as hp for constructed world and characters, especially because far too many situations end with the main character suddenly feeling enough anxt and mysery to fling lots of magic firey doom at whatever is confronting him at the time, then continue to winj about it later.
I can't think of many series that have an actual practicing magician as a main character. Memory sorrow and thorn and tad williams other series Shadowmarch, though they are exceptionally good fantasy are high fantasy and rather like game of thrones in that they occur in a very harsh medaeval world where magic exists, but the main characters don't themselves practice it, indeed in both series magic is sort of mysterious and like the magic in Lotr held at reserve.
Trudy Canavan's Black Magician series was the last book I read with a literal practicing magician as a main character and even involved a school of magic, but the first book was very ploddy and a bit ineffective, I also didn't like the fact that the main character pretty useless at taking any affirmative action. The third book of the series when everything goes to hell was indeed very good, but you have to wade through a hole lots of prevarication to get there, ---- though I will give Canavan credit in that the magic in her books isn't just instant deus ex like it is in some fantasy series and does have limits, although it's not as well defined as in hp.
Actually one of the best books that features magic and a magic school I've read recently was The rythmetist by Brandon sanderson, which is about a sort of steam punk style world and a school where people learn to create magic drawings with chalk that can affect the real world. The magic there is very strictly defined in geometric terms, and an amusing point is the main character isn't actually a rythmetist, but would very much like to be, however Sanderson has once again just done the first book of a series and we're waiting on more.
lastly of course no discussion about magic would be complete without two names from the classic world of British fantasy. Diana wynne jones and Susan cooper. Jones stuff often features literal magic, and there magic is treated very much in a casual, everyday almost witchish way, she also has the ability to write wonderfully selfish characters. Several involve people learning magic and though they aren't similar to hp sinse the magic is far wilder and more strange, they also have something wonderfully charmingly everyday about them.
susan cooper is different again, sinse there, in her dark is rising series, magic is very dark, very mysterious but also extremely strictly defined on rather shamanic rules, like no crossing the threashold without permission. Magic is also highly restricted in it's use, it wouldn't be used for anything everyday and only comes up in the battle against the light and the dark which is the focus of her books. definitely one if you like really nice writing and many celtic and arthurian elements. Oh, and forget entirely about the dark is rising film, like most hollywood adaptations it should be cast into the oobliette of infinity and banished from all existance! ;d.
With our dreaming and singing, Ceaseless and sorrowless we! The glory about us clinging Of the glorious futures we see,
Our souls with high music ringing; O men! It must ever be
That we dwell in our dreaming and singing, A little apart from ye. (Arthur O'Shaughnessy 1873.)