FYI most of the best monitors use DVI not HDMI. HDMI is only really useful if you need to transfer both video and sound over a single secure wire, it's more or less designed for playing bluRay movies.
My standard recommendation these days (for casual gamers who want a decent all around monitor) would be the dell u2412m and the dell u2312hm. They are good for the money. They use e-ips panels
The hp zr24w and zr2440w also look good.
The best 24" monitors would be: the dell u2410, the hp zr2475, the Asus PA256Q, and the NEC 241w, but these are probably overkill for what you want. They use h-ips and p-ips panels.
If you are a super hard-core gamer, I might suggest a TN panel from ASUS. Though I think most regular (non-super) hard-core...