View foreign key constraints so I can delete a table
And here's how to generate the script @Shark showed for all the tables you want to drop. Let's say you have the following tables:

USE tempdb;
GO

CREATE TABLE dbo.z(z INT PRIMARY KEY); -- we won't delete this one

CREATE TABLE dbo.a
(
 a INT PRIMARY KEY FOREIGN KEY REFERENCES dbo.z(z)
);

CREATE TABLE dbo.b
(
 b INT PRIMARY KEY, 
 a INT FOREIGN KEY REFERENCES dbo.a(a)
);

CREATE TABLE dbo.c
(
 c INT PRIMARY KEY, 
 b INT FOREIGN KEY REFERENCES dbo.b(b), 
 a INT FOREIGN KEY REFERENCES dbo.a(a)
);

-- we won't drop this table either, but we'll need to drop
-- the constraint:

CREATE TABLE dbo.d
(
 d INT, 
 c INT FOREIGN KEY REFERENCES dbo.c(c)
);


But we only want to delete a, b, and c.

-- load the tables you want to delete into a table variable:

DECLARE @tables_to_delete TABLE (t NVARCHAR(512));

INSERT @tables_to_delete VALUES('dbo.a'),('dbo.b'),('dbo.c');


DECLARE @sql NVARCHAR(MAX) = N'';

-- build a list of the foreign keys you'll have to drop first:

SELECT @sql += CHAR(13) + CHAR(10) + N'ALTER TABLE ' 
    + QUOTENAME(OBJECT_SCHEMA_NAME(f.parent_object_id))
    + '.' + QUOTENAME(OBJECT_NAME(f.parent_object_id))
    + ' DROP CONSTRAINT ' + QUOTENAME(f.name) + ';'
FROM sys.foreign_keys AS f
INNER JOIN @tables_to_delete AS t
ON f.referenced_object_id = OBJECT_ID(t.t);

-- then the DROP TABLE commands:

SELECT @sql += CHAR(13) + CHAR(10) + N'DROP TABLE '
    + t + ';'
FROM @tables_to_delete;

PRINT @sql;
-- EXEC sp_executesql @sql;


Result (the constraint names will look different if you run this):

ALTER TABLE [dbo].[b] DROP CONSTRAINT [FK__b__a__2D27B809];
ALTER TABLE [dbo].[c] DROP CONSTRAINT [FK__c__a__30F848ED];
ALTER TABLE [dbo].[c] DROP CONSTRAINT [FK__c__b__300424B4];
ALTER TABLE [dbo].[d] DROP CONSTRAINT [FK__d__c__32E0915F];
DROP TABLE dbo.a;
DROP TABLE dbo.b;
DROP TABLE dbo.c;


When you're happy about the result, uncomment the EXEC line.

(Note, you won't be able to validate the script in its entirety when using PRINT if the script is very large. The script is truncated by Management Studio because it still has an archaic limit to how many characters it will show. The string won't be truncated like this when it gets passed to sp_executesql.)